Roger completely forgot the words to 'I'm In Love With My Car' and after an "instrumental part" Freddie realized Roger's blackout and had to sing a couple of lines to help him.
Freddie Mercury (lead vocals, piano, tambourine, acoustic guitar),
Brian May (electric guitar, backing vocals, acoustic guitar, piano),
Roger Taylor (drums, lead vocals, backing vocals, timpani, tambourine),
John Deacon (bass guitar)