They join old singer when playing clubs (9,5)

I believe the answer is:

soldering irons

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'they' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'join old singer when playing clubs' is the wordplay.
'join' says to put letters next to each other.
'when playing' indicates anagramming the letters.
'clubs' becomes 'irons' (iron is a kind of club).
'old'+'singer'='oldsinger'
'oldsinger' anagrammed gives 'soldering'.
'soldering' put next to 'irons' is 'SOLDERING-IRONS'.

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I've seen this clue in The Guardian.

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