Trendy tunes start in dirigible (7)
I believe the answer is:
airship
'dirigible' is the definition.
(synonyms)
'trendy tunes start' is the wordplay.
'trendy' becomes 'hip' (both can mean fashionable).
'tunes' becomes 'airs' (air can mean a piece of music).
'start' means one lot of letters go next to another.
'hip' after 'airs' is 'AIRSHIP'.
'in' is the link.
(Other definitions for airship that I've seen before include "mode of transport" , "Flying machine" , "Dirigible" , "Old flier" , "Conveyance" .)