Music of the highest rank? (9)
I believe the answer is:
classical
This could be a double definition.
'music' is the first definition.
(classical music is a kind of music)
'highest rank?' is the second definition.
'classical' can be an answer for 'rank?' (thesaurus). I'm not certain of the 'highest' bit.
'of the' acts as a link.
Can you help me to learn more?
(Other definitions for classical that I've seen before include "of Rome?" , "Like some music" , "Accepted as standard" , "from 1750 to 1800" , "Like ancient Greek or Roman art" .)