Record poem about isles for part of series (7)
I believe the answer is:
episode
'for part of series' is the definition.
(eg part of a TV series)
'record poem about isles' is the wordplay.
'record' becomes 'EP' (abbreviation for extended play record).
'poem' becomes 'ode' (ode is a type of poem).
'about' is a charade indicator (letters next to each other).
'isles' becomes 'is' (abbreviation for isles).
'ode' put after 'is' is 'isode'.
'ep'+'isode'='EPISODE'
(Other definitions for episode that I've seen before include "Musical passage" , "Incident or one part of a story" , "Instalment of broadcast serial" , "Instalment; event" , "Incident in a story or part of a serial" .)