It's warbled in Los Angeles (4)
'it's warbled' is the definition.
(I've seen this before)
'in los angeles' is the wordplay.
'in' says the answer is hidden in the clue.
'SANG' is hidden in the letters of 'los angeles'.
(Other definitions for sang that I've seen before include "Took part in a vocal performance", "Chanted", "Chinese organ", "Celebrated", "Warbled".)