Musical group tight, having consumed two pints, missing second note (6,7)
I believe the answer is:
string quartet
'musical group' is the definition.
(string quartet is a kind of musical group)
'tight having consumed two pints missing second note' is the wordplay.
I cannot really understand how this works, but
'second' could be 's' (common abbreviation) and 's' is found in the answer.
'note' could be 'te' (musical note as in do re mi fa so la ti) and 'te' is found within the answer.
'two pints' could be 'quart' (unit of liquid equal to two pints) and 'quart' is found in the answer.
The remaining letters 'tring' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for string quartet that I've seen before include "Chamber music group" , "Chamber music for four" .)