LSD fired up musicians (8)
I believe the answer is:
fiddlers
'musicians' is the definition.
(fiddler is a kind of musician)
'lsd fired up' is the wordplay.
'up' is an anagram indicator.
'lsd'+'fired'='lsdfired'
'lsdfired' with letters rearranged gives 'FIDDLERS'.
(Other definitions for fiddlers that I've seen before include "Tinkerers or violinists" , "Old King Cole's trio" .)