[scarecrowbob]

"Musicians get better by practice and tackling harder and harder pieces, not by switching instruments or genres, nor by learning more and varied easy pieces. Ditto almost every other specialty inhabited by experts or masters."

At some level maybe.

But for most folks I know, there is a plateau that you get to when you only play a single instrument in a single situation.

It is true that if you're intermediate at something, just practicing more will get you further.

But learning piano (and the instrument's linear layout presenting a more visual set of tonal relationships) helped my pedal steel playing immensely.

Learning cello (and the instrument's focus on pitch forced the lack of frets, compared to guitar) immensely helped my harmony singing.

Playing in blues bands that call tunes I've never heard on the fly (which necessitated listening intently to the form and hoping to intuit changes before hearing them) helped my musicianship in more scripted forms because I had to both listen much nore closely to the other players and to develop my music theory chops so I could anticipate changes and develop language to describe common musical passages I needed to play on-the-fly.

I feel like knowing several programming languages and frameworks yields similar kinds of reactive benefits.

[LeonB]

“Range” by David Epstein goes into this at length.

Studies about “mastery” that indicate you should stick to a single instrument tend to be about classical music where you’re playing (generously: ‘interpreting’) existing pieces, which is very easy to assess.

But qualitative research on successful creative musicians from a far broader range of genres demonstrates exactly what you’re saying: a range of experience in different instruments and genres is highly beneficial.