Member of Shadows performing as member of Beatles (8)
I believe the answer is:
harrison
'member of beatles' is the definition.
(George Harrison)
'member of shadows performing' is the wordplay.
'member of shadows' becomes 'harris' (Jet Harris, bassist of The Shadows).
'performing' becomes 'on' (I've seen this in other clues).
'harris'+'on'='HARRISON'
'as' is the link.
(Other definitions for harrison that I've seen before include "Rex ---; --- Ford" , "Ford possibly" , "George maybe" , "-- Birtwistle, composer" , "Member of group" .)