Fail to win with song and no longer know what is happening (4,5)

I believe the answer is:

lose track

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'no longer know what is happening' is the definition.
I know nothing about this answer so I can't judge whether it can be defined by this definition.

'fail to win with song' is the wordplay.
'fail to win' becomes 'lose' (synonyms).
'with' is a charade indicator (letters next to each other).
'song' becomes 'track' (I've seen this before).
'lose'+'track'='LOSE TRACK'

'and' acts as a link.

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I've seen this clue in The Daily Express.

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