Soprano singer, one covering last of jazz pieces (7)
I believe the answer is:
scherzi
'pieces' is the definition.
(scherzo is a kind of piece)
'soprano singer one covering last of jazz' is the wordplay.
'soprano' becomes 's' (musical abbreviation).
'singer' becomes 'cher' (Cher is a US musician).
'one' becomes 'I' (Roman numeral).
'covering' is an insertion indicator.
'last of' indicates one should take the final letters.
The final letter of 'jazz' is 'z'.
'cher'+'i'='cheri'
'cheri' enclosing 'z' is 'cherzi'.
's'+'cherzi'='SCHERZI'
(Other definitions for scherzi that I've seen before include "vigorous movements" , "In music, brisk lively movements" , "Playful symphony pieces" , "Lively movts. (It., mus.)" , "Fast dance movements" .)