...it's music marketed at teens primarily, occasionally hurried and juvenile (8)
I believe the answer is:
immature
'juvenile' is the definition.
('immature' can be similar in meaning to 'juvenile')
'it's music marketed at teens primarily occasionally hurried' is the wordplay.
'primarily' indicates taking the first letters.
'occasionally' means one should take alternating letters.
The first letters of 'its music marketed at teens' is 'immat'.
The alternate letters of 'hurried' are 'ure'.
'immat'+'ure'='IMMATURE'
'and' acts as a link.
(Other definitions for immature that I've seen before include "Not yet fully grown or developed" , "Lacking in development" , "Not yet adult or fully developed" , "Like childish behaviour" , "Undeveloped - unripe" .)