Lively piece of music (7)
(Other definitions for toccata that I've seen before include "Baroque keyboard composition" , "Touching piece" , "Keyboard piece emphasising touch" , "lively piece" , "Musical work designed to show player's technique" .)
'lively piece of music' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for capriccio that I've seen before include "A lively piece of music" , "Lively work" , "Free instrumental composition, played with improvisation" , "Lively composition" , "Strauss opera" .)