Should union head quietly give respectful nod to violinist's V-sign? (5)

'respectful nod to violinist's v-sign?' is the definition.
I know nothing about this answer so I can't tell whether this works.

'should union head quietly' is the wordplay.
I cannot really understand how this works, but
'union' could be 'u' (common abbreviation as in 'Trades Union Congress') and 'u' is present in the answer.
'quietly' could be 'p' (p for piano and quiet) and 'p' is found in the answer.
The remaining letters 'bow' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

'give' acts as a link.

Can you help me to learn more?