Line in opera beginning to drift went this way and that (8)

'went this way and that' is the definition.

'line in opera beginning to drift' is the wordplay.
'line' becomes 'l'.
'in' is an insertion indicator.
'opera' becomes 'salome' (I've seen this before**).
'beginning to' suggests taking the first letters.
The first letter of 'drift' is 'd'.
'l' put inside 'salome' is 'slalome'.
'slalome'+'d'='SLALOMED'