I think that "She Makes Me" (one of Brian May's most hauntingly beautiful compositions in my humble opinion) was also written in a sleep. 

Also, if you've watched "Classic Albums - A Night at the Opera", there was an explanation about the "strange chords" of "Bohemian Rhapsody". Apparently Freddie had a piano as the headboard of his bed and used to write music when he woke up during the night (a tape recorder conveniently by his bedside). He would stretch his arms backwards and play. That's where the chords come from - he was playing backwards in his sleep! 

V.