May also tuned the guitar's lowest E2 string down to a D2 note for a moodier sound. At over eight minutes in length, it is also Queen's longest song with vocals, though the untitled instrumental track from Queen's last studio album, Made in Heaven, is about 14 minutes longer. It is a heavy and dark number with a strong progressive rock influence and challenging lead vocals. The vocal, and later instrumental canon was produced by early tape delay devices. May spent several days putting it together, and it includes a vocal canon sung by Freddie Mercury.

Portions of the song were recorded but abandoned during sessions for Queen II. On the show In the Studio with Redbeard, which spotlighted A Night at the Opera, he explained that he wrote the song after a dream he had about a great flood while he was recovering from being ill while recording Sheer Heart Attack, using the dream as his source for some of the lyrics. 'The Prophet's Song' was composed by Brian May (working title 'People of the Earth') and is the longest Queen song, at 8 minutes and 17 seconds, exceeding Bohemian Rhapsody by 2 minutes and 22 seconds. 'The Deluge', frontispiece to Gustave Doré's illustrated edition of the Bible after having a dream about a flood, Brian May was inspired to write a song about it.

Queen a night at the opera prohets song