Teacher turning to take on very loud musical pieces (5)

I believe the answer is:

riffs

'musical pieces' is the definition.
(a riff is short melody)

'teacher turning to take on very loud' is the wordplay.
'teacher' becomes 'sir' (way of addressing a male teacher).
'turning' is a reversal indicator.
'to take on' indicates putting letters inside.
'very loud' becomes 'ff' (musical abbreviation).
'sir' in reverse letter order is 'ris'.
'ris' enclosing 'ff' is 'RIFFS'.

I've seen this clue in The Guardian.

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