Mingle in club owned by Jagger, we hear (8)
I believe the answer is:
intermix
'mingle' is the definition.
(I know this)
'club owned by jagger we hear' is the wordplay.
'club' becomes 'inter' (Inter Milan, Italian football club).
'owned by jagger' becomes 'Mick's' (belonging to Mick Jagger).
'we hear' indicates a 'sounds like' (homophone) clue.
'micks' sounds like 'mix'.
'inter'+'mix'='INTERMIX'
'in' is the link.
(Other definitions for intermix that I've seen before include "Mingle" , "Stir" , "Blend together" .)