Bilbao got hammered for performance regardless (9)
I believe the answer is:
obbligato
'performance regardless' is the definition.
I can't tell whether this definition defines the answer.
'bilbao got hammered' is the wordplay.
'hammered' is an anagram indicator (slang term for drunk).
'bilbao'+'got'='bilbaogot'
'bilbaogot' anagrammed gives 'OBBLIGATO'.
'for' is the link.
Can you help me to learn more?
(Other definitions for obbligato that I've seen before include "Has to be done" , "Compulsory (music)" , "important passage of music" , "Instrumental part integral to a piece of music - I go to blab (anag)" , "Part that must be played" .)