Notes introducing opening of Salome or Sadko around this building? (2,5)
I believe the answer is:
la scala
'building?' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'notes introducing opening of salome or sadko around' is the wordplay.
I cannot quite see how this works, but
'notes' could be 'las' (more than one la, a musical note) and 'las' is found in the answer.
'around' could be 'ca' (circa) and 'ca' is found in the answer.
The remaining letters 'la' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'this' acts as a link.
(Other definitions for la scala that I've seen before include "music centre" , "A Callas may find way to Milan's famous opera house" , "place to sing" , "noted venue?" , "Italian opera house" .)