the music will stand for itself.

Could you show the context in which that was used?

It goes like this: "His new band is brilliant. The music will stand for itself." Does it help?

I would say it means that the music the band produces is so good, everyone will know the band is brilliant just by hearing it. It isn't going to need any superfluous hype to prove itself.

Oh, I get it. Thank you so much!