Empty apology after firm takes her mum travelling to see a musical (6,7)
I believe the answer is:
summer holiday
'musical' is the definition.
(1963 musical)
'empty apology after firm takes her mum travelling to see a' is the wordplay.
I cannot quite understand how this works, but
'empty' could be 'o' and 'o' is present in the answer.
an anagram of 'her' is 'erh' which is present in the answer.
an anagram of 'mum' is 'umm' which is within the answer.
'a' is present in the answer.
This explanation may well be incorrect...
(Other definitions for summer holiday that I've seen before include "Mid-year break" , "Film" .)