Titters infuriated some bars at the end (7)
I believe the answer is:
stretti
'some bars at the end' is the definition.
(stretto is a concluding musical passage)
'titters infuriated' is the wordplay.
'infuriated' indicates an anagram (letters upset or infuriated).
'titters' anagrammed gives 'STRETTI'.
(Other definitions for stretti that I've seen before include "musical pieces" , "Musical passages" , "Pieces of music" , "fugal devices" .)