Expressing disapproval, no good disappearing all together (5)
I believe the answer is:
Here is my best explanation:
'all together' is the definition.
(I've seen this before)
'expressing disapproval no good disappearing' is the subsidiary indication.
'expressing disapproval' becomes 'tutting' (I've seen this before).
'no good' becomes 'ng' (abbreviations).
'disappearing' is a deletion indicator.
'tutting' with 'ng' taken away is 'tutti'.
(Other definitions for tutti that I've seen before include "Musical instruction for all instruments to play", "Composer of Carmina Burana", "All the orchestra to play together", "Everybody (mus.)", "With all performers", "For all of 7 [ORCHESTRA]", "All together (music)", "All (stage direction)", "when everyone plays" and "For all performers".)