Sort of rock music, trendy, to pass on (5)
I believe the answer is:
indie
'sort of rock music' is the definition.
'indie' can be an answer for 'music' (independent music). I am not sure about the 'sort of rock' bit.
'trendy to pass on' is the wordplay.
'trendy' becomes 'in' ('in' can mean fashionable).
'to pass' becomes 'die' (as in passing away).
'on' says to put letters next to each other.
'in'+'die'='INDIE'
Can you help me to learn more?
(Other definitions for indie that I've seen before include "Non-mainstream record label" , "Unaffiliated (pop record label)" , "minor label" , "(Pop group) not affiliated to a major recording company" , "not linked to major label" .)