Possible Clues:

• Lead guitarist to go rehearsing or dancing ...
• Did he solo My Sweet Lord or share playing with e.g. Ringo?
• Member of group, nasty ogre, he being imprisoned in fortress
• Redeployed here, go to infiltrate military position, as one of four in group
• Beatle hero Ringo's 'gear' -- swinging!
• Pop-star's guinea for Lewis's partner performing