How about combining words?
Musically accurate!
I can’t see how speakers can evade either adjective if it is to be considered as very good or beyond.
Speakers should sound like the musical information they need to create. Horns = horns. Trumpets should not sound like trombones. Drums = drums. Bongos ought not sound like Congas. Snares not akin to Tom Tom. Tom tom shouldn’t be heard as Tiffany. Reeds and strings? Should sound like reeds and strings. Tenor sax should not sound like alto sax.
And Cow bells should always be distinctive. Even when beaten repeatedly during ‘Don’t fear the Reeper’. If Christopher Walken is banging on one or not.
Connotatively musical and accuracy can be separated by gulfs or oceans. Its been said here already. Euphony on the one side for musical and the flip side of accuracy can imply clinical or analytical. Or worse still, sterile.
Musically accurate, if set side by each, seems to resolve any vague inferences and implications, and what I look for in loudspeakers.