Untrustworthy type reportedly calls off a solo passage (7)
I believe the answer is:
cadenza
'solo passage' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
(Other definitions for cadenza that I've seen before include "Solo display passage" , "Virtuoso solo passage in a concerto" , "Virtuoso passage in concerto, etc" , "Virtuoso's solo" , "Elaborate passage for soloist" .)