It's cold, which isn't really a surprise for London in December.
He pulls out his violin and tests the strings, tuning them gently to account for the cold. Once he's finished, he draws his bow across, and the music starts.
He leans his chin on the violin, listening to the sounds ringing through the crisp twilight air of London. Shoppers and tourists pass him, but he pays them no mind, not allowing his mind to focus on anything but the notes and melodies rising to the invisible stars.
A few coins drop into the case next to him, and he lifts his eyes to acknowledge the person who gave them. The woman smiles coyly and then walks on. He watches her go and small facts about her life (single mother, young son, two cats, secretary) flit through his head unbidden. He just sees and knows, even when he's not concentrating.
He ends the song and starts another. He has seen other musicians out on the street with electric violins and amplifiers and distortion pedals, but none of those ever sound quite as good as the real thing, as good as the real wood vibrating with the sound, sending echoes out to the people (banker, a young couple [both students], librarian, cashier) listening, watching. Couples pause as they walk past on their way to whatever restaurant or show or concert, just to hear a few lines before walking on.
This isn't something he does often. It's something he does when the walls of his flat are closing in, when his own breathing feels too loud in a room that's too small. It happens when he's beyond boredom, beyond the mind-melting tediousness that is everyday life and he wants something wholly different.
He finishes a piece with a small flourish and carefully retunes his violin as he smiles slightly at the smattering of applause. More people have dropped coins into his case, and he makes sure he looks each person in the eye as they do. (Teacher, policewoman, grocer, nurse.)
He tunes his violin again, adjusting the pegs just slightly, and then plays "Carol of the Bells." This one's a bit tricky, but he can do more with it, drawing out the phrases or repeating the chorus as he likes. He spots one or two people with camera phones and carefully doesn't look up at them, keeping his eyes on his fingers or on the people dropping coins in his case.
Twice he gets "skimmed," but he doesn't really mind (another student and an out of work construction worker). The money doesn't matter to him anyway; he's just out here for some air and happened to bring his violin. The people don't get much.
He moves on to another, slower piece. The crowd disperses a bit, people going on their way to wherever they were heading (home, the shops, a lover's) when he hears footsteps come up on his right. (John. He knows John's stride, his footsteps, doesn't even have to look.)
"So this is where you disappeared to," a voice says when he puts down the violin.
"Hello, John."
"It's bloody freezing."
"I know." He loosens his bow and crouches to stow it in its compartment. He gathered the coins from the bottom of the case. "Here, hang on to these." He settles his violin into the case, wipes it down gently, makes sure everything's in its proper place, and closes the case, flipping the latches closed. Sherlock stands.
John takes the coins, counting them. Steady, dependable John (who's just come out to shop for presents).
"Jeez, Sherlock, you've got nearly £30 here. You got this just from playing on the street for a couple of hours?" John says, counting the coins again. Sherlock puts his scarf on and pulls on his gloves, noticing the chill for the first time since he got his violin out.
"I thought we might go to dinner," Sherlock says, smiling down at John. John smiles back at Sherlock.
"That sounds good," John replies. "It's a good thing I've already got your Christmas present, then, isn't it?"
Christmas morning, Sherlock opens his gifts from John.
A tin of rosin (the same kind he always uses) and a brand new (higher quality) bow.
"Thank you, John," Sherlock said, examining the bow. He smiles at John, but he's already planning what to play first, both to try out the bow and to please John.