It's no good interrupting an SOS for singing (5)
I believe the answer is:
songs
'it's no good interrupting an sos for singing' is the definition.
I can't judge whether this defines the answer.
'it's no good interrupting an sos' is the wordplay.
'it's no' becomes 'n' (common abbreviation).
'good' becomes 'g' (abbreviation).
'interrupting' is an insertion indicator.
'n'+'g'='ng'
'ng' going inside 'sos' is 'SONGS'.
Can you help me to learn more?
(Other definitions for songs that I've seen before include "Airs" , "Vocal pieces" , "Words with music" , "Melodies with words" , "Verse" .)