A London orchestra too! (4)

I believe the answer is:

also

'too' is the definition.
('also' can be a synonym of 'too')

'a london orchestra' is the wordplay.
'london orchestra' becomes 'lso' (london symphony orchestra).
'a'+'lso'='ALSO'

(Other definitions for also that I've seen before include "What's more" , "item's rarely used now for this" , "Item" , "in accompaniment" , "To boot" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app