[duped]

Music absolutely uses more than two channels. Or less. You don't need special "support" either any more than flac, you just decode it and write the bytes to your output buffer.

[eviks]

How prevalent is music with >8 channels???

And it wasn't "special", it's just apps don't support playing the format

[duped]

You don't pick an archival format for the common case, you pick it for all cases. But to answer the question, virtually every film soundtrack for the last 10 years.

[eviks]

That doesn't make sense, you don't pick to suffer from poor support if you have a zero ore tiny niche case for it, you preserve it for that case only.

And you didn't answer the question, this discussion is about personal music libraries, like in the case of op collection of 25 years.

I'd bet almost all of them are stereo and not >8 channels