UnScramble this Word: i f d m o f e?

Questions

john lennon, paul mccatney, ringo star and _______?

what christian rock group recorded such songs as 'honestly' and 'to hell with the devil'?

what rock group recorded such smash hits as 'come sail away' and 'the grand illusion'?

what group performed such songs as 'i swear' and 'i can love you like that'?

name the group that did the song-turned-pop-culture-icon 'stairway to heaven'?