It's a well-known fact that Sherlock Holmes neglects anything that isn't to do with the Work.
Or rather, well-known to him, perhaps. Greg Lestrade will tell you that Sherlock never misses a chance to irritate his colleagues at the Yard and in particular, Anderson and Donovan—colleagues who, were Sherlock on good terms with them, would actually aid his progress at the Work rather than impede it. Sherlock incenses the Yard and scares away witnesses, and no one could convince Greg that any of that actually helps with the Work.
John Watson will tell you, perhaps most honestly, that Sherlock does indulge interests other than the Work, if generally only when it suits him. Such as the times when, admittedly rarely, Sherlock bestirs himself to go to the shops to get more milk or eggs or tea or any number of other things the two of them happen to need. Sherlock will always claim it's for an experiment (which is after all just another extension of the Work), or that it happens to be one of those rare moments when his transport actually requires sustenance. And if it happens to be at just the moments when John is about to claw the walls from tea withdrawal, well, he pretends not to notice.
Then there are the times when Sherlock drives away John's girlfriends. Sherlock drives away John's girlfriends all the time, indeed seems to take a particular vicious pleasure in the pastime, but sometimes John thinks that he is especially quick to do so when they're about to bore John to tears from talking about their small dogs or daytime telly or something equally mindless. John knows Sherlock hates nothing more than being bored, and the idea that Sherlock would take special care in protecting him from boredom is oddly touching. Sherlock would protest that he interferes so that John will be free to assist him with the Work. John just rolls his eyes when Sherlock isn't looking and lets him believe what he likes.
Mycroft Holmes will tell you, haughtily, that Sherlock takes a particular interest in the violin, which is proof enough that the Work is not all that matters to him. Sherlock is not a professional violinist, and shows no ambition for the career, but his proficiency in the instrument is cultivated enough that he could easily become one if he chose. No one with that amount of skill could claim to be as single-minded as Sherlock does.
If Sherlock could hear his brother's thoughts on that matter, he would predictably call him a fat bore who understands nothing. Mycroft is one to talk about single-mindedness or his ability to assess it, as he notably only cares about ruling the world yet detests anything remotely to do with "legwork." Mycroft embodies a laziness that Sherlock finds utterly abhorrent, because Mycroft is too lazy even to acknowledge the actual truth of the matter. To Sherlock, it is pathetic and so undeniably like Mycroft to count the violin as anything approaching taxing, when he is merely jealous of Sherlock's native ability.
Because it is only native ability, Sherlock will tell you. The violin could never interfere with the Work; playing it isn't even difficult enough to do so, and anyway it forms an integral part of his thought process. Sherlock is well aware of his brother's relentlessly logical assertions that the violin is a developed skill like any other and the fact that Sherlock has nourished it to the degree he has is deeply significant in some way. He is even inclined to agree with him to a certain extent—not that he would ever tell Mycroft this. Mycroft does not need any more inflation of his own ego than he already possesses.
Besides, though Sherlock might at least partially concede Mycroft that particular point, Mycroft is dreadfully wrong on other counts.
What Mycroft gets wrong about Sherlock could fill several large books, thinks Sherlock smugly, but what is especially relevant here is one particular fact about Sherlock that Mycroft doesn't understand, that no one in fact understands, and that Sherlock has never seen fit to enlighten them about.
And so it is on one inexcusably dull August day that Sherlock rouses from his prone position on the sofa and takes his violin from its case to rub the bow with rosin and tune the strings slowly, even reverently. The act of tuning is an almost sacred ritual to Sherlock; that instant when the strings sing with the proper consonance always seems to resonate with all of London.
John, being John, fails to grasp the inherent gravity of the moment. "Oh, so we've reached that stage in the boredom cycle, have we?"
Sherlock, naturally, does not reply. He has made it a point never to reply to John's more rhetorical questions, as if attempting to train him in his own brand of verbal efficiency. Not that John is ever aware of any such thing, having evidently decided in turn to train Sherlock in the pointless minutiae of ordinary human conversation. Sherlock tunes the E string higher; fussy thing that, always wanting to go out of tune at the slightest atmospheric fluctuation. He'll have to replace it soon.
John winces at the sound. "I think I'd best get ready," he says, getting up from his chair. "I've got a date tonight. Lisa, you know, you've met her."
Sherlock surfaces enough to say, "Yes, I know. She's a nurse and a Doctor Who fanatic with two cats and a model train hobby. She'll want you to come and meet her university friends for drinks after dinner."
John pauses on his way to the stairs. "I probably shouldn't even ask how you know that."
Sherlock closes his eyes, running the bow over the strings. Obvious. The E string sounds true at last and he waits a moment, savouring the vibrations, before setting the violin carefully aside and getting up to rummage through his collection of sheet music and the scattered messy staves of his own compositions. He's in the mood for something eighteenth-century today; Mozart perhaps, though Schubert or even Brahms might also be acceptable. At any rate, today is a day for music with structure, music with theme and progression, and at the moment, Mozart seems the ideal choice. He's rarely in the mood for anything quite as structured as Mozart, but London's crime has had an irritatingly long dry spell, and if he cannot currently seek clarity and logic directly through the Work, he'll take its equal in music.
Sherlock pauses in his digging with loose pages flung about the sitting room, his reverie unravelling a bit. Something is wrong, wrong like a string that won't tune. "John! John, where are they!"
There is no reply, so Sherlock approaches the staircase and begins pounding on the wall with his fist. "John!"
"For God's sake, what, Sherlock?" John emerges from behind the corner, a toothbrush in his hand.
"Where have you put them, what have you done with them?"
John folds his arms and glares at Sherlock, his toothbrush dripping foam on the carpet. "Mrs Hudson threw them out weeks ago, or don't you remember? Don't be such a toddler."
"What?" says Sherlock, a split second before the penny drops. "No, not the cigarettes, John, don't be an idiot! What have you done with my violin concerti?" He will never be persuaded to use the English plural of that word. He doesn't care how pretentious that makes him.
John just stares, and suddenly Sherlock is very aware that the man has a gun and is very good at using it. "Why would I have anything to do with your violin, Sherlock? That, as you never hesitate to remind me, is not my area. Now kindly piss off before you give Mrs Hudson a heart attack, and leave me to get ready for my date." He turns, and Sherlock hears a door slam.
Sherlock stands there for a moment, feeling abashed, before turning to look through his stash of scores again, though at a more subdued pace. He finally finds the concerto book wedged behind a bookcase and eases it out, smoothing his hand over the bent pages. John has no right to be offended. The violin is not his area, and how is that Sherlock's fault? Is he expected to sugar-coat it for him? His own life would certainly have been a lot easier if he'd had people to talk to who were more like him. Really, Sherlock is in the worse position in this scenario.
He momentarily forgets his ruffled—not feelings, never feelings—upon finding what he has been searching for in the book. Mozart's violin concerti. He'll start with the first one; he's always appreciated the outer movements' quick passagework and expectant cadences. He has just settled the book open on the music stand when he registers John's footsteps on the stairs. He spins around, unconsciously twirling the bow in one hand, violin tucked under his arm. "John."
John gives him a tense smile. "Find them, did you?"
"John, I'm—sorry." The word crawls out of his mouth, childish and slow. He wants to swallow it again.
John sighs. "I'd better get going." He walks to the door, then turns back. "It's fine, Sherlock. I'll see you later, all right?" The door closes quietly, a final echo of a chord.
Sherlock stands motionless, bow drooping helplessly at his side. He should feel better, but there's still something in his stomach he can't identify—one of those wretched feelings he pretends he doesn't have. He turns to the window. On the street below, John is getting into a cab, off to meet the latest in a parade of dull girlfriends. It's better, really, that John isn't here with him, because it is still true that the violin really isn't his area, even if Sherlock has been less than tactful in pointing that out to him. Sherlock just wishes that fact wouldn't hurt so much.
He turns back to the music on the stand, feeling off-balance. He plucks at the violin's strings, hoping to find a sour note, some lingering imperfection he can smooth out with the tuning pegs, but they remain consonant, perfect. No matter, he can begin now. It's not ideal, not the smooth organization of melodic ideas he's been anticipating, but he'll still feel better when he's done.
He begins the concerto abruptly, skipping the orchestral exposition; he can hear the orchestra perfectly well in his head, but without one actually present, waiting for it is a bit pointless. His playing is halting, ungraceful, accents falling on all the wrong beats. He hasn't played Mozart in a while, but really. This is embarrassing. He makes it as far as the first modulation before breaking off at the establishing cadence, scowling at the page in frustration. Nothing for it but to start again.
So he starts again. And, once he has made it to the final cadenza and has loosed his misshapen mess of an improvisation all over the flat, again, until finally the notes arrange themselves smoothly between his fingers, flowing runs of semiquavers issuing from beneath the bow like silk. This is easy now, but better, this is order.
He can just hear Mycroft's snide Mozart, isn't Mozart too simple for you, Sherlock? Goodness, you may as well play Corelli and have done with it.
Sherlock firmly tells the mental Mycroft to go away, his fingers dancing across the neck of the violin, itching for that increasingly elusive cadence. How like Mycroft to see these moments as mere contests with some imagined authority—and he thinks Sherlock has a competitive streak. Of course, Sherlock does have a competitive streak, but it only ever manifests against his brother, and anyway it has never included the violin, that being always firmly Sherlock's area and not Mycroft's, the interfering sod. If Sherlock wants to play Mozart, or Mendelssohn, or even Schoenberg or Crumb or Penderecki, he'll do it regardless of the (inevitable) protestations. He has done so, just to annoy Mycroft, and he is never disappointed in the reaction. Mycroft's sensibilities are perpetually stuck in the nineteenth century, so naturally he has no appreciation for the avant-garde.
And John, what would John say about this lean, elegant music, or indeed about anything else Sherlock might play? Sherlock doesn't know the answer to that, especially given John's earlier outburst, but now, held in the thrall of tension and release, of notes that proceed inexorably into one another, he's finding it difficult to be bothered too much by that. The final chords of the imagined orchestra sound in his head, the bow sings its harmony with them, and the movement is over, almost by its own volition. Sherlock grins, savagely, his thoughts still in flux, as he turns the pages back to begin again.
He has barely begun the exposition anew when the door opens and John walks in. Sherlock frowns but keeps playing, and John sits down in front of him. John's clothing is clean and unwrinkled, almost exactly the state as when he left not thirty minutes ago. Though he is early, he bears no obvious signs of a date gone awry, so Sherlock dismisses him for the moment and turns his attention back to the music, the notes tugging at him like living things. He's approaching the cadenza again, and is determined this time to give it the proper weight.
The invisible orchestra pulls at Sherlock's mind, and he plays ferociously to keep up with it until he reaches the uneasy balance of the cadenza. The voice of the violin climbs and cascades, dizzily, impassioned like the voice of a human being, before compressing into a long trill. The cadenza finishes, Sherlock's shoulders relax, and the resultant inertia brings the movement to its end.
The silence is the release of a held breath, and John pauses to give it the proper acknowledgment before applauding. "Well done," he says, his eyes warm.
Sherlock bows floridly. "You're home early," he says. It's one of those hateful rhetorical statements, but Sherlock would never think himself above bending his own rules.
"Lisa called to cancel while I was on my way there," John says. "Apparently she heard from Blanche who heard from Kate who heard from Sarah that I have a tendency to get myself and my girlfriends kidnapped, while my mad flatmate likes to keep dismembered body parts in the freezer." He doesn't sound angry about it though, regarding Sherlock with a faintly resigned smile. "It was good you told me about the model trains. I don't think I could have stood it if she'd tried to get me into those too. And to add to that, I'm allergic to cats."
Sherlock's lips twitch up at the corners, as they frequently do whenever John has said something amusing and Sherlock is pretending he doesn't have emotions. "I know. That was what convinced me the hairs on her clothing were from a pair of cats she owned and not dogs. Dogs have never made your eyes water like that."
John laughs. "I don't know why I didn't figure that out."
"Because—"
John holds up one hand. "I know, because I'm an idiot."
"Quite."
John rolls his eyes. "So, what were you playing, then? It's rather different from what you usually play. It's . . . I dunno, emphatic."
Sherlock tilts his head. "Emphatic?"
"Yeah, it's—oh hang it, Sherlock, I don't know the terminology, I haven't played an instrument since primary school." John gestures with both hands in effort to explain. "It's like—it has drama to it. It feels like it's going somewhere and it lets you know when it gets there. You know. Emphatic." His hands drop. "I don't know what kind of music that is or who wrote it; I'm not an expert. I know I've never heard you play it before. But I liked it a lot. It's very you, because it seeks a definite conclusion. It's like hearing you think." His voice fades as he finishes, and he looks slightly embarrassed.
For a moment Sherlock is silent as he considers this. Unbidden, a theme races in his head and suddenly, it modulates. Sherlock laughs, and John startles at the sound. "John. John, you are not an idiot at all. You are brilliant."
John raises his eyebrows. "I am, am I? I had better cherish this moment, Sherlock Holmes has told me I'm brilliant."
"You are," says Sherlock. "You are infinitely more brilliant than Mycroft, because Mycroft understands nothing about form or balance or cadential progression and he's too lazy to want to."
John blinks at the apparent non sequitur in invoking Sherlock's brother, but seems to decide to let it go. "I thought we'd established already that I am in fact an idiot."
Sherlock waves a dismissive hand. "Doesn't matter. New data."
"New data."
"Yes, John," says Sherlock. "It's part of the scientific process, that should hardly surprise you."
"Right, my mistake." John speaks as if he were the one who has just received proof of something rather than Sherlock and practically radiates the smugness of his discovery. "So who did write that music you were playing?"
"Hmm? Oh, Mozart."
"Mmm." John hums the incipit to the first movement of Eine kleine Nachtmusik. "That's him, right?"
Sherlock smiles, all pretences of stoicism long gone by this point. "Yes." He stirs, abruptly, to tuck violin and bow carefully back into the case, while the stray pages of music get shoved into more or less the messy configuration by the window they had occupied before.
John watches this from his comfortable position on the sofa. At last he says, "I know we haven't any cases on, and my date was a bit pants, but . . . fancy some Chinese and crap telly? You can have a go at deducing all the plot lines."
Sherlock grins. It really is quite extraordinary how lucky he is that John is not Mycroft. A cadence, then a codetta. Maybe this is how a day with John Watson is meant to end. He joins him on the sofa, while John digs out his phone to order the Chinese.
He can take a moment away from the Work for this point of resolution. Because though it is indeed a well-known fact how singularly devoted Sherlock Holmes is to his Work, Sherlock is a man of reason. He would never hesitate to remind you of the dangerous fallacies born out of well-known facts.
A/N: This story was partially inspired by the idea that Sherlock thinks in music the way other people think in words or pictures (I know composers who are like that). It was also something of a defense of Mozart, for those who might think Sherlock would be attracted more to the virtuosity of Paganini and the like. Charles Rosen called music of the Classical era "dramatic" in its formal structure, which I think is perfectly true—and perfectly fitting of Sherlock's thought processes.