Throng see idol performing in Savoy Opera (3,10)
I believe the answer is:
the gondoliers
'savoy opera' is the definition.
'the gondoliers' can be an answer for 'opera' (I've seen this before). I am unsure of the 'savoy' bit.
'throng see idol performing' is the wordplay.
'performing' is an anagram indicator.
'throng'+'see'+'idol'='throngseeidol'
'throngseeidol' anagrammed gives 'THE GONDOLIERS'.
'in' is the link.
Can you help me to learn more?
(Other definitions for the gondoliers that I've seen before include "G&S operetta" , "opera" , "Gilbert and Sullivan operetta" .)