String of Pearls — part of Meyerbeer opera (4)
I believe the answer is:
rope
'string of pearls' is the definition.
(I've seen this before)
'part of meyerbeer opera' is the wordplay.
'part of' indicates the answer is hidden within the clue.
'ROPE' is hidden in the letters of 'meyerbeer opera'.
(Other definitions for rope that I've seen before include "Enough to hang one?" , "Guy" , "Give a man enough . . . . and he'll hang himself" , "Tier" , "Length of material used to tie or secure things" .)