It wasn't often that he came home to have tea with his mother, but Sherlock had been an absolute nightmare, it was all he could do to get out of there.
She had few requests in life so he felt the urge to grant her this even though it'd been since the middle of med school since he'd played.
He placed the cello between his thighs and thought hard about what to play and closed his eyes, he wasn't a savant, but he knew music.
Drawing the bow he played his instrument, the cello, with his all, just for her.