The Sinful Ones by Fritz Leiber

As if the street laps puffed out clouds of luminous dust which rose three or four stories. Above that, dark walls going up toward a few dull stars.
    They passed a music store. Jane’s walk slowed to an indecisive drift. Through the open door Carr glimpsed a mahogany expanse crossed by serried walks of ivory and ebony. There were uprights, spinets, baby grands. Jane walked in. The sound of their footsteps died as they stepped onto the thick carpet.
    Whoever else was in the store was out of sight somewhere in the back, where a soft glow glamorized shelves of record albums and a row of cubicles. Jane sat down at one of the pianos. Her thin fingers moved for a while over the keys, nervously questing. The taut, talon-suggestive cords in the back of her hands underlined the expression in her face. Then her back stiffened, her head lifted, and there came the frantically rippling, opening arpeggios of the third movement of Beethoven’s Moonlight Sonata.
    She didn’t play it any too well. She struck false notes and the general rendering was somewhat raucous. The impression was that of a student pianist who by a passionate determination has succeeded in grappling passably with a piece beyond her real technical proficiency.
    For she did manage to extract from it a feeling of wild, desperate wonder.
    Carr stopped speculating as to why a clerk didn’t emerge and at least give them a sizing-up glance.
    Surely if the composer had ever meant this to be moonlight, it was moonlight illuminating a white-pinnacled ocean storm, through rifts in ragged clouds.
    Jane’s lips were tightly bitten together. Her eyes seemed to be frantically searching out the next notes in an invisible score. Her body shook as her arms pounds from the shoulders.
    Suddenly it was over. In the echoing quiet Carr asked casually, “Is that more like it? The rhythm of life, I mean?”
    She made a little grimace as she got up.
    “Still too nice,” she said. “But there’s a hint.”
    They started out, Carr looking back over his shoulder.
    “Do you realize we haven’t exchanged a word with anyone tonight?” he said.
    She smiled wryly. “I think of pretty dull things to do, don’t I?” she said, and when he started to protest, “Yes, I’m afraid you would have had a lot more fun with Marcia…or with Midge’s girl-friend.”
    “Say, you do have a memory,” he said in surprise. “I wouldn’t have dreamed you’d—”
    He stopped. She had ducked her head. He couldn’t make out whether she was crying or laughing.
    “…Midge’s girl-friend…” he heard her repeat chokingly.
    “Don’t you know Tom Elvested?” he pressed suddenly.
    She disregarded the question and looked up at him with an uneven smile. “But since you haven’t got a date with anyone but me,” she said, “you’ll just have to make the best of my antisocial habits. Let’s see, this time of night I’m apt to wander off to Rush Street or to South State, to feel the hour and watch the dead faces. I could take you there, or—”
    “That’d be fine,” said Carr.
    “Or—”
    They walked close to the curb, skirting the crowd. They were passing the painfully bright lobby of a movie house, luridly placarded with yellow and purple swirls which seemed to have caught up in their whirlwind folds an unending rout of golden blondes, grim-eyed heroes, money bags, and detached grasping hands. Jane stopped.
    “Or I could take you in here,” she said.
    He obediently veered toward the box-office, but she kept hold of his arm and walked him past it into the outer lobby.
    “I will prove it to you,” she told him, half gaily, half desperately, he thought. “I showed you at the bar and the music shop, but—”
    Carr shrugged and held his breath for the inevitable.
    They walked straight past the ticket-taker and through the center-aisle door.
    Carr puffed out the breath and grinned. He thought, maybe she knows someone here.
    Or else—who knows?—maybe you could get away with almost anything