I can't remember the name of this webtoon, but here's a VERY general setup:

It starts with a guy buried up to his neck surrounded by gangster-ish looking people talking about how he shouldn't have signed a record contract with so-and-so (or something) and he's gonna pay for it. Then it flashes back to tell the story how he got into music and how he ended up in the predicament he finds himself in. I believe he starts out by chasing a girl who's into music and part of a small band that works out of a small studio apartment.

Any guesses?

What's There to Know?

That's it! Thank you so much.

(Downside is it doesn't look like it's being actively scanned. Oh well.)