Singer's cadenza ends in very old record (8)
I believe the answer is:
vocalist
'singer's' is the definition.
('vocalist' can be a synonym of 'singer')
'cadenza ends in very old record' is the wordplay.
'ends' means to remove the middle letters.
'in' is an insertion indicator.
'very' becomes 'v' (abbreviation).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'record' becomes 'list' (I've seen this before**).
'cadenza' with its centre removed is 'ca'.
'v'+'o'+'list'='volist'
'ca' put into 'volist' is 'VOCALIST'.
(Another definition for vocalist that I've seen is " Singer with a pop group".)