Unconventional rock band dismissive of new record's opening (5)
I believe the answer is:
queer
'unconventional' is the definition.
(I've seen this in another clue)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for queer that I've seen before include "Hinder or prevent" , "Odd; ruin (pitch)" , "Strange, curious" , "- - Street" , "Strange, odd" .)