Made a request for a very quiet German song (7)
I believe the answer is:
applied
'made a request' is the definition.
'applied' can be an answer for 'made' (applying is a kind of making). I'm not sure about the 'a request' bit.
'a very quiet german song' is the wordplay.
'very quiet' becomes 'pp' (musical abbreviation for pianissimo).
'german song' becomes 'lied' ('song' in German).
'a'+'pp'+'lied'='APPLIED'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for applied that I've seen before include "put to practical use" , "Put oneself forward, for a job say" , "Put into service, made work" , "Administered" , "Went for university place" .)