Slam Dunk, Beck Recommendations
I know you're thinking: "How is a sports manga similar at all to a music manga?" Well, while the subject matter differs entirely, the themes and characters are all too similar (in a good way). Both of these follow a young man with little direction in their lives; that is, until Sakuragi finds basketball and Koyuki finds music.
Other similarities: artwork starts off meh, gets better as it goes on (always fun seeing that transition); the authors' (Inoue Takehiko [Slam Dunk], Harold Sakuishi [Beck]) clearly depict their passion not only for storytelling, but for the hobby which is shown; and, finally, both were adapted into well-received