The first violin in German music, say (6)
I believe the answer is:
leader
'the first violin' is the definition.
(first violin is the leader in an orchestra)
'german music say' is the wordplay.
'german music' becomes 'lieder' (lieder are classical German songs).
'say' indicates a 'sounds like' (homophone) clue.
'lieder' sounds like 'LEADER'.
'in' acts as a link.
(Other definitions for leader that I've seen before include "One whose example is followed" , "Head of an orchestra" , "Head (of government, etc)" , "Chief or front man" , "Editorial - chief" .)