Virtuoso solo passage (7)
I believe the answer is:
cadenza
'virtuoso solo passage' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for cadenza that I've seen before include "Impromptu insertion in piece of music" , "Virtuoso performance" , "Soloist's virtuoso passage" , "Elaborate passage near the end of a piece of music" , "Virtuoso solo passage in a concerto" .)