There is a village in the South of England not far from the sea, which possesses a curious inn called "The Green Tower." Why it is called thus, nobody knows. This inn must in days gone by have been the dwelling of some well-to-do squire, but nothing now remains of its former prosperity, except the square grey tower, partially covered with ivy, from which it takes its name. The inn stands on the roadside, on the brow of a hill, and at the top of the tower there is a room with four large windows, whence you can see all over the wooded country. The exPrime Minister of a foreign state, who had been driven from office and home by a revolution, happening to pass the night in the inn and being of an eccentric disposition, was so much struck with this room that he secured it, together with two bedrooms, permanently for himself. He determined to spend the rest of his life here, and as he was within certain limits not unsociable, he invited his friends to come and stay with him on any Saturday they pleased, without giving him notice.
Thus it happened that of a Saturday and Sunday there was nearly always a mixed gathering of men at "The Green Tower, and after they had dined they would sit in the tower room and drink old Southern wines from the ex-Prime Minister's country, and talk, or tell each other stories. But the ex-Prime Minister made it a stringent rule that at least one guest should tell one story during his stay, for while he had been Prime Minister a Court official had been in his service whose only duty it was to tell him a story every evening, and this was the only thing he regretted of all his former privileges.
On this particular Sunday, besides myself, the clerk, the flute- player, the wine merchant (the friends of the ex-Prime Minister were exceedingly various), and the scholar were present. They were smoking in the tower room. It was summer, and the windows were wide open. Every inch of wall which was not occupied by the windows was crowded with books. The clerk was turning over the leaves of the ex-Prime Minister's stamp collection (which was magnificent), the flute-player was reading the score of Handel's flute sonatas (which was rare), the scholar was reading a translation in Latin hexameters of the "Ring and the Book" (which the ex-Prime Minister has written in his spare moments), and the wine merchant was drinking generously of a curious red wine, which was very old. "I think," said the ex-Prime Minister, "that the flute-player has never yet told us a story."
The guests knew that this hint was imperative, and so putting away the score, the flute-player said: "My story is called, 'The Fiddler.'" And he began:-- "This happened a long time ago in one of the German-speaking countries of the Holy Roman Empire. There was a Count who lived in a large castle. He was rich, powerful, and the owner of large lands. He had a wife, and one daughter, who was dazzlingly beautiful, and she was betrothed to the eldest son of a neighbouring lord. When I say betrothed, I mean that her parents had arranged the marriage. She herself--her name was Elisinde--had had no voice in the matter, and she disliked, or rather loathed, her future husband, who was boorish, sullen, and ill-tempered; he cared for nothing except hunting and deep drinking, and had nothing to recommend him but his ducats and his land. But it was quite useless for Elisinde to cry or protest. Her parents had settled the marriage and it was to be. She understood this herself very well.
"All the necessary preparations for the wedding, which was to be held on a splendid scale, were made. There was to be a whole week of feasting; and tumblers and musicians came from distant parts of the country to take part in the festivities and merry-making. In the village, which was close to the castle, a fair was held, and the musicians, tumblers, and mountebanks, who had thronged to it, performed in front of the castle walls for the amusement of the Count's guests. "Among these strolling vagabonds was a fiddler who far excelled all the others in skill. He drew the most ravishing tones from his instrument, which seemed to speak in trills as liquid as those of the nightingale, and in accents as plaintive as those of a human voice. And one of the inmates of the castle was so much struck by the performance of this fiddler that he told the Count of it, and the fiddler was commanded to come and play at the Castle, after the banquet which was to be held on the eve of the wedding. The banquet took place in great pomp and solemnity, and lasted for many hours. When it was over the fiddler was summoned to the large hall and bidden to play before the Lords and Ladies. "The fiddler was a strange looking, tall fellow with unkempt fair hair, and eyes that glittered like gold; but as he was dressed in tattered uncouth rags (and they were his best too) he cut an extraordinary and almost ridiculous figure amongst that splendid jewelled gathering. The guests tittered when they saw him. But as soon as he began to play, their tittering ceased, for never had they heard such music.
"He played--in view of the festive occasion--a joyous melody. And, as he played, the air seemed full of sunlight, and the smell of wine vats and the hum of bees round ripe fruit. The guests could not keep still in their places, and at last the Count gave orders for a general dance. The hall was cleared, and soon all the guests were breathlessly dancing to the divine lilt of the fiddler's melody. All except Elisinde who, when her betrothed came forward to lead her to the dance, pleaded fatigue, and remained seated in her chair, pale and distraught, and staring at the fiddler. This did not, to tell the truth, displease her betrothed, who was a clumsy dancer and had no ear for music. Breathless at last with exhaustion the guests begged the untiring fiddler to pause while they rested for a moment to get their breath.
"And while they were resting the fiddler played another tune. This time it was a sad tune: a low, soft tune, liquid and lovely as a human voice. A great hush came on the company. It seemed as if after the heat and splendour of a summer's day the calm of evening had fallen; the quiet of the dusk, when the moon rises in the sky, still faintly yellow in the west with the ebb of sunset, and pours on the stiff cornfields its cool, silvery frost; and the trees quiver, as though they felt the freshness and were relieved, and a breeze comes, almost imperceptible and not strong enough to shake the boughs, from the sea; and a bird, hidden somewhere in the leaves, sings a throbbing song.
"Everyone was spellbound, but none so much as Elisinde. The music seemed to be speaking straight to her, to pierce the very core of her heart. It was an inarticulate language which she understood better than any words. She heard a lonely spirit crying out to her, that it understood her sorrow and shared her pain. And large tears poured down her cheeks.
"The fiddler stopped playing, and for a moment or two no one spoke. At last Elisinde's betrothed gave a great yawn, and the spell was broken. " 'You play very well--very well, indeed,' said the Count.
" 'But that sad music is, I think, rather out of place to-day,' said the Countess. " 'Yes, let us have another cheerful tune,' said the Count.
"The fiddler struck up once more and played another dance. This time there was an almost elfish magic in his melody. It took you captive; it was irresistible; it called and commanded and compelled; you longed to follow, follow, anywhere, over the hills, over the sea, to the end of the world.
"Elisinde rose from her chair as though the spirit of the music beckoned her, but looking round she saw no partner to her taste. She sat down again and stared at the fiddler. His eyes were fixed on her, and as she looked at him his squalor and rags seemed to fade away and his blue eyes that glittered like gold seemed to grow larger, and his hair to grow brighter till it shone like fire. And he seemed to be caught in a rosy cloud of light: tall, splendid, young, and glowing like a god. "After this dance was over the Count rose, and he and his guests retired to rest. The fiddler was given a purse full of money, and the Count gave orders that he should be served refreshment in the kitchen.
"Elisinde went up to her bedroom, which overlooked the garden. She threw the window wide open and looked out into the starry darkness. It was a breathless summer night. The air was full of warm scents. Lights still twinkled in the village; now and again a dog barked, otherwise everything was still. She leant out of the window, and cried bitterly because her lot was loathsome to her, and she had not a friend in the world to whom she could confide her sorrow.
"While she was thus sobbing she heard a rustling in the bushes beneath; she looked down and she saw a face looking up towards her, a beautiful face, glistening in the moonlight. It was the fiddler.
" 'Elisinde,' he called to her in a low voice, 'if you want to escape I have the means. Come with me; I love you, and I will save you from your doom.' " 'I would come with you to the end of the world,' she said, 'but how can I get away from this castle?'
"He threw a rope ladder up to her. 'Make it fast to the bar,' he said, 'and let yourself down.'
"She let herself down into the garden. 'We can easily climb the wall with this,' he said; 'but before you come I must tell you that if you will be my bride your life will be hard and full of misery. Think before you come.'
" 'Rather all the misery in the world,' she said, 'than the awful doom that awaits me here. Besides which I love you, and we shall be very happy.'
"They scaled the wall, and on the other side of it the fiddler had two horses, waiting tied to the gate. They galloped through many villages, and by the dawn they had reached a village far beyond the Count's lands. Here they stopped at an inn, and they were married by the priest that day. But they did not stop in this village; they sought a further country, beyond reach of all pursuit. They settled in a village, and the fiddler earned his bread by his fiddling, and Elisinde kept their cottage neat and clean. For awhile they were as happy as the day was long; the fiddler found favour everywhere by his fiddling, and Elisinde ingratiated herself by her gentle ways. But one day when Elisinde was lying in bed and the fiddler had lulled her to sleep with his music, some neighbours, attracted by the sound, passed the cottage and looked in at the window. And to their astonishment they saw the fiddler sitting by a bed on which lay what seemed to them to be a sleeping princess; and the whole cottage was full of dazzling light, and the fiddler's face shone, and his hair and his eyes glittered like gold. They went away much frightened, and told the whole village the news.
"Now there were already not a few of the villagers who looked askance on the fiddler; and this incident set all the evil and envious tongues wagging. When the fiddler went to play the next day at the inn men turned away from him, and a child in the street threw a stone at him. Presently he was warned that he had better swiftly fly or else he would be drowned as a sorcerer.
"So he and Elisinde fled in the night to a neighbouring village. But soon the dark rumours followed them, and they were forced to flee once more. This happened again and again, till at last in the whole country there was not a village which would receive them, and one night they were obliged to take refuge in a barn, for Elisinde was expecting the birth of her child. That night their child was born, a beautiful little boy, and an hour afterwards Elisinde smiled and died. "All that night the villagers heard from afar a piteous wailing music, infinitely sad and beautiful, and those that heard it shuddered and crossed themselves. "The next day the villagers sought the barn, for they had resolved to drown the sorcerer; but he was not there. All they found was the dead body of Elisinde, and a little baby lying on some straw. The body of Elisinde was covered with roses. And this was strange, for it was midwinter. The fiddler had disappeared and was never heard of again, and an old wood-cutter, who was too old to know any better, took charge of the baby.
"I will tell you what happened to it another day."
* * * * *
"We wish to hear the end of your story," said the ex-Prime Minister to the fluteplayer.
"Yes," said the scholar, "and I want to know who the fiddler was." This conversation took place at the Green Tower two weeks after the gathering I have already described. The same people were present; but there was another guest, namely, the musician, who, unlike the flute- player, was not an amateur. "The child of Elisinde and the fiddler," began the flute-player, "was, as I have already told you, a boy. The woodcutter who took pity on him was old and childless. He brought the baby to his hut, and gave it over to the care of his wife. At first she pretended to be angry, and said that nothing would persuade her to have anything to do with the child, and that it was all they could do to feed themselves without picking up waifs in the gutter; but she ended by looking after the baby with the utmost tenderness and care, and by loving it as much as if it had been her own child. The baby was christened Franz. As soon as he was able to walk and talk there were two things about him which were remarkable. The first was his hair, which glittered like sunlight; the second was his fondness for all musical sounds. When he was four years old he had made himself a flute out of a reed, and on this he played all day, imitating the song of the birds. He was in his sixth year when an event happened which changed his life. He was sitting in front of the woodcutter's cottage one day, when a bright cavalcade passed him. It was a nobleman from a neighbouring castle, who was travelling to the city with his retainers. Among these was a Kapellmeister, who organised the music of this nobleman's household. The moment he caught sight of Franz and heard his piping, he stopped, and asked who he was.
"The woodcutter's wife told him the story of the finding of the waif, to which both the nobleman and himself listened with great interest. The Kapellmeister said that they should take the child with them; that he should be attached to the nobleman's house and trained as a member of his choir or his string band, according to his capacities. The nobleman, who was passionately fond of music, and extremely particular with regard to the manner of its performance, was delighted with the idea. The offer was made to the woodcutter and his wife, and although she cried a good deal they were both forced to recognise that they had no right to interfere with the child's good fortune. Moreover, the gift of a purse full of gold (which the nobleman gave them) did not make the matter more distasteful.
"Finally it was settled that the child should go with the nobleman then and there; and Franz took leave of his adopted parents, not without many and bitter tears being shed on both sides.
"Franz travelled with the nobleman to a large city, and he became a member--the youngest--of the nobleman's household. He was taught his letters, which he learnt with ease, and the rudiments of music, which he absorbed with such astounding rapidity, that the Kapellmeister said that it seemed as if he already knew everything that was taught him. When he was seven years old, he could not only play several instruments, but he composed fugues and sonatas. When the nobleman invited the magnates of the place to listen to his musicians, Franz, the prodigy, was the centre of interest, and very soon he became the talk of the town. At the age of ten he was an accomplished organ player, and he played with skill on the flute and the clavichord.
"He grew up a tall and handsome lad, with clear, dreamy eyes, and hair that continued to glitter like sunlight. He was happy in the nobleman's household, for the nobleman and his wife were kind people; like the woodcutter they were childless and came to look upon him as their own child. He was a quiet youth, and so deeply engrossed in his music and his studies that he seemed to be quite unaware of the outside world and its inhabitants and its doings. But although he led a retired, studious life, his fame had got abroad and had even reached the Emperor's ears.
"When Franz was seventeen years old it happened that the Court was in need of an organist. The Emperor's curiosity had been aroused by what he had heard of Franz, and one fine day the youth was summoned to Court to play before his Majesty. This he did with such success that he was appointed organist of the Court on the spot.
"He was sad at leaving the nobleman, but there was nothing to be done. The Emperor's wish was law. He became Court organist and he played the organ in the Imperial chapel during Mass on Sundays. As before, he spent all his leisure time in composing music.
"Now the Emperor had a daughter called Kunigmunde, who was beautiful and wildly romantic. She was immediately spellbound by Franz's music, and he became the lodestar of her dreams. Often in the afternoon she would steal up to the organ loft, where he was playing alone, and sit for hours listening to his improvisations. They did not speak to each other much, but ever since Franz had set eyes on her something new had entered into his soul and spoke in his music, something tremulous and strange and wonderful.
"For a year Franz's life ran placidly and smoothly. He was made much of, praised and petted; but now, as before, he seemed quite unaware of the outside world and its doings, and he moved in a world of his own, only he was no longer alone in his secret habitation, it was inhabited by another shape, the beautiful darkhaired Princess Kunigmunde, and in her honour he composed songs, minuets, sonatas, hymns, and triumphal marches. As was only natural, there were not wanting at Court persons who were envious of Franz, his talent, and his good fortune. And among them there was a musician, a tenor in the Imperial choir, called Albrecht, who hated Franz with his whole heart. He was a dark-eyed, darkhaired creature, slightly deformed; he limped, and he had a sinister look as though of a satyr. Nevertheless he was highly gifted and composed music of his own which, although it was not radiant like that of Franz, was full of brilliance and not without a certain compelling power. Albrecht revolved in his mind how he might ruin Franz. He tried to excite the envy of the courtiers against him, but Franz was such a modest fellow, so kindly and good-natured, that it was not easy to make people dislike him. Nevertheless there were many who were tired of hearing him praised, and many who were secretly tired of the perpetual beauty and radiance of Franz's music, and wished for something new even though it should be ugly.
"An opportunity soon presented itself for Albrecht to carry out his evil and envious designs. The Court Kapellmeister died, and not long after this event a great feast was to be held at Court to celebrate Princess Kunigmunde's birthday. The Emperor had offered a prize, a wreath of gilt laurels, as well as the post of Court Kapellmeister to him who should compose the most beautiful piece of music in his daughter's honour. Franz seemed so certain of success that nobody even dared to compete with him except Albrecht.
"When the hour of the contest came--it took place in the great throne- room before the Emperor, the Empress, their sons, their daughters, and the whole court after the banquet--Franz was the first to display his work. He sat down at the clavichord and sang what he had composed in honour of the Princess. He had made three little songs for her. Franz had not much voice, but it had a peculiar wail in it, and he sang, like the born and trained musician that he was, with that absolute mastery over his means, that certain perfection of utterance, that power of conveying, to the shade of a shade, the inmost spirit and meaning of the music which only belong to those great and rare artists whose perfect art is alive with the inspiration that cannot be learnt.
"The first song he sang was the call of a home-going shepherd to his flock on the hills at sunset, and when he sang it he brought the largeness of the dying evening and the solemn hills into the elegant throne-room. The second song was the cry of a lonely fisherman on the river at midnight, and as he sang it he brought the mystery of broad starlit waters into the taper-lit, gilded hall. The third song was the song of the happy lover in the orchard at dawn. And when he sang it he brought the smell of dewy leaves and grass, the soaring radiance of spring and early morning, to that powdered and silken assembly. The Court applauded him, but they were astonished and slightly disappointed, for they had expected something grand and complicated, and not three simple tunes. But the nobleman who had educated Franz, and his Kapellmeister, who were among the guests, wept tears in silence.
"Albrecht followed him. The swarthy singer sat down to the instrument and struck a ringing chord. He had a pure and infinitely powerful tenor voice, clear as crystal, loud as a clarion, strong, rich, and rippling. He sang a love-song he had composed himself. He called it 'The Homage of King Pan to the Princess.' It was voluptuous and vehement and sweet as honey, full of bold conceits and audacious turns and trills, which startled the audience and took their breath away. He sang his song with almost devilish skill and power; and his warm, captivating voice rang through the room and shook the tall window- panes, and finally died away like the vibrations of a great bell. The whole Court shouted, delirious with applause, and unanimously declared him to be the victor. A witty courtier said that Marsyas had avenged himself on Apollo; but the nobleman and his Kapellmeister snorted and sniffed and said nothing. Albrecht was given the prize and appointed Kapellmeister to the Court without further discussion. "When the ceremony was over, Franz, who was indifferent to his defeat, went to the chapel of the palace, and lighting a candle, walked up into the organ loft. There he played to himself another song, a hymn he had composed in honour of Princess Kunigmunde. It was filled with rapture and a breathless wonder, and in it his inmost soul spoke its unuttered love. He had not sung this song in public, it was too sacred. As he played and sang to himself in a low voice he was aware of a soft footstep. He started and looked round, and there was the Princess, bright in silk and jewels, with a pink rose in her powdered hair. She took this rose and laid it lightly on the black keys.
" 'That is the prize,' she said. 'You won it, and I want to thank you. I never knew music could be so beautiful.'
"Franz looked at her, and said 'Thank you.' He had risen from his seat and was about to go, but the light of his candle caught Princess Kunigmunde's brown eyes (which were wet with tears), and something rose like fire in his breast and made him forget his bashfulness, his respect, and his sense of decorum. " 'Come with me,' he said, in a broken voice. 'Let us fly from this Court to the hills and be happy.'
"But the Princess shook her head sadly, and said: 'Alas! It is impossible. I am betrothed to the King of the Two Sicilies.'
"Then Franz mastered himself once more, and said: 'Of course, it is impossible. I was mad.'
"The Princess kissed her hand to him and fled.
"At that moment Franz heard a noise in the nave of the chapel; he looked over the gallery of the organ loft, and saw sidling away in the darkness the dim figure of a deformed man.
"That night Princess Kunigmunde had a strange dream. She thought she was transported into a beautiful southern country where the azure sky seemed to scintillate with the dust of myriads and myriads of diamonds, and to sparkle with sunlight like dancing wine. The low blue hills were bare and sparsely clothed with delicate trees, and the fields, sprinkled with innumerable red, yellow, white and purple flowers, were bright as fabulous Persian carpets. On a grassy knoll before her the rosy columns of a temple shone in the gleaming dust of the atmosphere. Beside her there was a running stream, on the bank of which grew a bay-tree. There was a chirping of grasshoppers in the air, a noise of bees, and a delicious warm smell of burnt grass and thyme and mint.
"Near the stream a man was standing; he was an ordinary man, and yet he seemed to tower above the landscape without being unusually tall; his hair was bright as gold, and his eyes, more lustrous still, reflected the silvery blue sky and shone like opals. In his hands he held a golden lyre, and around him a warm golden cloud seemed to rise, on a transparent aura of light, like the glow of the sunset. In front of him there stood a creature of the woods, a satyr, with pointed ears, cloven hoofs, and human eyes, in his hairy hands holding a flute made out of a reed.
"Presently the satyr breathed on his flute and a wonderful note trembled in the air, soft, low, and liquid. The note was followed by others, and a stillness fell upon Nature; the birds ceased to sing, the grasshoppers were still, the bees paused. All Nature was listening and the Princess was conscious in her dream that there were others besides herself listening, unseen shapes and sightless phantoms; a crowd, a multitude of attentive ghosts, that were hidden from her sight. The melody rose and swelled in stillness; it was melting and ravishing and bold with a human audacity. As she listened it reminded her of something; she felt she had heard such sounds before, though she could not remember where and when. But suddenly it flashed across her that the music resembled Albrecht's song; it was Albrecht's song, only transfigured as it were, and a thousand times more beautiful in her dream than in reality. More beautiful, and at the same time as though it belonged to the days of youth and spring which Albrecht had never known. The satyr ceased playing and the pleasant noises of the world began once more. The shining figure who stood before him looked on the satyr with divine scorn and smiled a radiant, merciless smile. Then he struck his lyre and Nature once more was dumb.
"But this time the magic was of another kind and a thousand times more mighty; a song rose into the air which leapt and soared like a flame, imperious as the flashing of a sword, triumphant as the waving of a banner, wonderful as the dawn and fresh as the laughing sea. And once more Princess Kunigmunde was aware that the music was familiar to her. She had heard something like it in the chapel that evening, when in the darkness Franz had played and sung the hymn that he had composed in her honour. Only now it was more than human, unearthly and divine. As soon as he ceased an eclipse seemed to darken the world, a thick cloud of rolling darkness; there was a crash of thunder, a flash of lightning, and out of the blackness came a piteous, human cry, the cry of a creature in anguish, and then a faint moaning.
"Presently all was still, but the dark cloud remained, and she heard a mocking laugh and the accents of a clear, scornful voice (she recognised the voice, it was the voice of Albrecht), and the voice said: 'Thou hast conquered, Apollo, and cruelly hast thou used thy victory; and cruelly has thou punished me for daring to challenge thy divine skill. It was mad indeed to compete with a god; and yet shall I avenge my wrong and thy harshness shall recoil on thee. For not even gods can be unjust with impunity, and the Fates are above us all. And I shall be avenged; for all thy sons shall suffer what I have suffered; and there is not one of them that shall escape the doom and not share the fate of Marsyas the Satyr, whom thou didst cruelly slay. The music and the skill which shall be their inheritance shall be the cause to them of sorrow and grief unending and pitiless pain and misery. Their life shall be as bitter to them as my death has been to me. Their music shall fill the world with sweetness and ravish the ears of listening nations, but to them it shall bring no joy; for life like a cruel blade shall flay and lay bare their hearts, and sorrow like a searching wind shall play upon their souls and make them tremble, even as the scabbard of my body trembled in the breeze; and just as from that trembling husk of what was once myself there came forth sweet sounds, so shall it be with their souls, shivering and trembling in the cold wind of life. Music shall come from them, but this music shall be born of agony; nor shall they utter a single note that is not begotten of sorrow or pain. And so shall the children of Apollo suffer and share the pain of Marsyas. "The voice died away, and a pitiful wail was heard as of a wind blowing through the reeds of a river. And the Princess awoke, trembling with fear of some unknown and impending disaster.
"The next morning Franz, as he walked into the chapel to practice on the organ, was met by two soldiers, who bade him follow them, and he was shut up in the prison of the palace. No word of explanation was given him; nor had he any idea what the crime might be of which he was accused, or of his ultimate fate. But in the evening, when the gaoler's daughter brought him his food, she made him a sign, and he found in his loaf of bread a rose, a file, and a tiny scroll, on which the following words were written; 'Albrecht denounced you. Fly for your life. K.' Later, when the gaolers had gone to sleep, the gaoler's daughter stole to his cell. She brought him a rope, and a purse full of silver. He filed the bars and let himself down into a narrow street of the city.
"By the time the sun rose he had left the city far behind him. He journeyed on and on till he passed the frontier of the Emperor's dominions and reached a neighbouring State. By the time he came to a city he had spent his money, and he was in rags and tatters; nevertheless, he managed to earn his bread by making music in the streets, and after a time a well-to-do citizen who noticed him took him into his house and entrusted him with the task of teaching music to his sons and of playing him to sleep in the evening. Franz spent his leisure hours in composing an opera called 'The Death of Adonis,' into which he poured all the music of his soul, all his love, his sorrow, and his infinite desire. He lived for this only, and during all the hours he spent when he was not working at his opera he was like a man in a dream, unconscious of the realities around him. In a year his opera was finished. He took it to the Intendant of the Ducal Theatre in the city and played it to him, and the Intendant, greatly pleased, determined to have it performed without delay. The best singers were allotted parts in it, and it was performed before the Arch-Duke and his Court, and a multitude of people. "The music told the story of Franz's love; it was bright with all his dreams, and sorrowful with his great despair. Never had such music been heard; so sweet, so sunlit in its joys, so radiant in its sadness. But the Arch-Duke and his Court, startled by the new accent of this music, and influenced by the local and established musicians, who were envious of this newcomer, listened in frigid silence, so that the common people in the gallery dared not show signs of their delight. In fact, the opera was a complete failure. Public opinion followed the Co