He stops in the doorway and stares: some blonde guy he doesn't know is the source of the drumming. It's an infectious beat, one that Tony aches to record and break down to its individual pieces, writing out the notes for the snares, the bass drum, the crash cymbals - he balls his hands into fists and walks into the room, telling himself not to notice the blonde himself, the sweat on his neck, the dog tags swinging through the air as he bobs his head, the too-big hands that look like they could break the sticks easily.
"Hey," Tony says, trying to pull back the annoyance that led him in here: he's been trying to work, but no, this guy has to practice his drumming in the middle of the night, and okay, if you're going to be up at this hour you should either be playing obnoxious music or out partying and he's getting off-track here. He's trying to be annoyed and it's not working because whoever this guy is, he's good. Good at drumming, good-looking...
The guy opens his eyes, promptly looks guilty, and stops drumming.
"Sorry," he says, ducking his head, looking properly ashamed of himself. "I didn't know anyone was in here."
"I live upstairs," Tony says, which leads directly to his next question: "How you'd get in here?"
Okay, he's technically lying about living upstairs. He actually lives in a mansion with butlers and a better workshop then he'll ever have here, but there are reasons why he's not there and why he's bunking here instead.
"Phil said I could let myself in and play anytime - no one would mind it if I played at night," says the guy, and oh that son of a bitch. How is he on a first-name basis with Coulson when Tony's never met him before? And yeah, Tony can just see Coulson tilting his head and giving this stranger permission to play anytime Tony's likely to be working and liable to be bothered.
"He finally found a replacement drummer?" Tony asks instead of getting angry at the guy.
"When I'm back in form, yes," the guy says before getting up and off the stool. He holds out a hand. "It's nice to meet you. I'm Steve Rogers."
"Tony," Tony says, shaking his hand. "Tony Stark."
His grip is strong, and he holds on for almost too long before pulling his hand back and looking sheepish. "I'm really sorry about waking you up, Mr. Stark."
Tony shrugs. "I wasn't sleeping. And call me Tony."
"Okay, Tony. Would you mind if I kept practicing? I could stop for the night..."
"It's fine," Tony says, and because despite himself he's beginning to like the guy, he saunters over to where his trumpet is stored, flips open the latches and pulls out his instrument. "I could use a little practice myself."
Music: the only area in Tony's life where he'll admit to needing more practice.
"Of course I play, Coulson wouldn't let me stay otherwise," Tony says, wetting his lips. "Go ahead, play something. I'll follow."
He turns back to Steve, fitting the mouthpiece in his trumpet, and grins. This might turn out to be fun after all.
Steve sits back on the stool, and within seconds he's drumming again, closing his eyes and oh, good for him, he's playing a beat that Tony can easily improvise into with something jazzy.
That's the rest of the night: Steve drums, Tony plays trumpet, and occasionally Tony quiets to let Steve solo and occasionally Steve reduces his playing back to a simple bass line so Tony can show off, and to Tony's surprise they fit together really well.
The lights are dim, just enough to see each other by, and Tony steals glimpses of Steve as he plays, watches as he gives himself over to the drumming entirely, watches his dog tags sway along with the beat, and he goes walking with his trumpet, across to the bar to get himself a one-handed glass of water. Steve opens his eyes as he does, watching him as he gulps down the water and refills it, coming back and setting it on a stool so he can keep playing.
Tony meets his eyes and grins between notes, and Steve grins back. Tony winks, because he likes the guy.
Steve winks back, blushes, and keeps drumming. It's not long before he closes his eyes again, getting back into the swing of it.
That's when Tony decides that he needs Steve's number, because if Coulson doesn't keep him, Tony will.