Cas stops by the door, and the gentle tinkling of piano notes float around his ears. The most beautiful interpretation of Chopin's Nocturne Op. 9 No. 2, in a style he's sure can never be replicated. Since they discovered the bunker housed a little upright piano, Sam's been down in the basement learning pieces whenever the job grants him some free time. It was odd, at first, to see someone of his stature sitting on the stool, patiently pressing his fingers to the keys and his feet on the pedals, but there was a delicacy to his movements that were usually suppressed when he was hunting. This feels like Sam, Cas muses, watching him make annotations on a piece of sheet music. He's in his element; this is what he'd be passionate about, what he'd root himself in, if they lived in any kind of normality. And yet as soon as he thinks it, he wonders. Although it's not the typical white picket fence life the Winchesters used to chase after all those summers ago, it's steady, and considering the way Sam and Dean act while safe inside the bunker's walls, it might as well be home.
Dean likes to sit in on Sam sometimes, watching him play with a permanent half-smile resting on his face as the streams of melody pass him by. He loves the variability of the instrument, especially in his brother's hands, because it feels like he's soaring. Sam can make the music arc high and sweet so it nibbles gently at Dean's ear, or swoop down so the low bass notes thrum in his chest. Occasionally, it occurs to Dean to ask him to shift sideways a little and make room for him to sit beside him. Sam always tries to coax him into a duet when this happens, but he's yet to take him up on the offer.
Dean's not present today, though, so it's Cas who enters the room to make up for it. Without meaning to, his feet patter out a rhythm that matches the Chopin – an unintentional metronome if there ever were one – which causes Sam to look up in amusement. He hasn't been sleeping too well, Cas can tell, because the dark rings under his eyes are threatening to encroach upon his cheeks, and his eyebrows droop as he tips his head down to check his fingering. Admittedly, insomnia was an inevitability, a small side effect of going nine-tenths of the way through the trials only to find out he had to forgo everything he'd done and force his body into convalescence. Cas believes the soothing, regular quality of the piano makes it easier for Sam to cope, but the reality is much simpler.
Sam loves the instrument. It's a hobby he'd wanted to take up through all of high school, but the way they lived back then didn't allow for any such commitment. He'd dared to ask John to pay for lessons at his then-school once, and was met with a resolute "no". His hopes were temporarily quashed then, but he'd never let go of the idea, merely letting it settle in the back of his head, ready for revival someday. He didn't know that 15 years later, in the midst of the greatest tragedy between heaven and hell since the apocalypse, he'd finally realise a schoolboy dream.
The floorboards creak slightly as Cas appears beside the piano, nodding his head in time with the piece. Sam finishes playing the final note, adding a flourish at the end and bowing his head to his one man audience.
"Keep going," Cas urges, lost in the nuances in expression of the cadence. Sam coughs, almost embarrassedly, and pulls the folder that's sitting on the top of the piano towards him.
"Actually, I was going to play one of my own, uh, compositions," he mumbles while leafing through the sheets of paper. There's enough in there to last for a long time; pieces he's found on the internet, film and musical scores from old bookshops, and a few sheets filled with scribbles of his own making – groups of notes here and there, a half-finished melody, and, occasionally, a whole sheet of complete music.
Cas leans in, resting his elbows on the faded wood, indicating his approval. He watches Sam with a mixture of content and curiosity as he makes his way through the staves, his fingers trailing across the keys. They're as light as running footsteps and the sounds they create are sublime. Cas finds himself surprised that the piece is so Sam; even if he couldn't see who was playing, he thinks he could recognise it as a Sam Winchester composition. There's something in the individual notes and the way they come together in the phrasing that is incredibly haunting, but at the same time blissful undercurrents of laughter and mirth undulate in the accompaniment.
The two of them are so engrossed in the music that they don't move or speak after the piece's tentative end. Sam's gaze is occupied by some object in the distance, while Cas' eyes glaze over with unspoken emotion. Cas is the first to break the silence.
"That was…nothing short of beautiful," and Sam looks at him like the sun just burst through the clouds after a miserable day, with a smile to match. He's been working on it for some time now, and though it's only a short piece, he's grateful that Cas was the first one to hear it the whole way through, mistakes and all.
"Does it have a title?" Sam thinks for a minute, and shakes his head. "Haven't even thought about names," he says, faintly surprised. He'd been concentrating wholly on the progressions and the textures and the improvements, so the title had hardly crossed his mind. They were difficult, anyway, because how could he possibly embody his music, with all its layers and complexities, in only a few words? It would be like trying to look at the stars from the bottom of a well. Cas doesn't seem to think so, though, because his lips shape into a suggestion.
"How about 'Augury of Fall'?" And in an instant, Sam knows it's perfect. Because it's like the wind gliding through the trees that scatters the leaves skyward in whirls of crisp yellow and brown, like the last tinges of green escaping the warmth and sanctuary of summer, and the flocks of birds that billow through overcast skies. He exhales slowly and shakes his head, not quite believing how well Cas' title crowns the piece.
"It's decided, then," Sam nods, still smiling.