Put off by act that included a song (7)
I believe the answer is:
delayed
'put off' is the definition.
(I've seen this in another clue)
'act that included a song' is the wordplay.
'act' becomes 'deed' (deed is a kind of act).
'that included' is an insertion indicator.
'a song' becomes 'lay' (lay is a kind of song).
'deed' enclosing 'lay' is 'DELAYED'.
'by' acts as a link.
(Other definitions for delayed that I've seen before include "Shelved" , "Deferred, postponed" , "Made late" , "Held up, back" , "Detained, help up" .)