A significant missing piece of the Queen puzzle is soon going to made available. Two of their classic performances -- one of which has never been officially released -- will see the light of day in audio and video formats on Sept. 8 in the form of 'Queen: Live at the Rainbow '74.'

Both concerts took place at London's 3,000-seat Rainbow Theatre. The first was on March 31, 1974, the final show of the tour in support of their second album, 'Queen II.' Recorded by Roy Thomas Baker, the performance was originally planned to be the band's third album, but was scrapped once work had begun on 'Sheer Heart Attack.'

Over the years, the legend of the show has grown among Queen fanatics, as it marks the transitional period between those first two albums and the impending glory years just ahead. Following the huge success of the 'Killer Queen' single in the fall of '74, Queen returned to the Rainbow for two sold-out shows, which were also recorded and filmed. Highlights from those concerts, which were released on video only in England as part of 1992's 'Box of Tricks,' are also included in this new set. The full track listing can be found below.

'Queen: Live at the Rainbow '74' has been newly mixed and mastered, and will be available in the usual variety of formats, including double-CD, DVD, Blu-ray, and the obligatory 'Super Deluxe Collector's Edition,' which will feature all of the above as well as a 60-page hardback book, miscellaneous memorabilia, concert program, poster, and more. Vinyl and digital versions will also be available.

'Queen: Live at the Rainbow '74' Track List

Disc One: March 31, 1974

1. 'Procession'
2. 'Father to Son'
3. 'Ogre Battle'
4. 'Son and Daughter'
5. 'Guitar Solo'
6. 'Son and Daughter (Reprise)'
7. 'White Queen (As It Began)'
8. 'Great King Rat'
9. 'The Fairy Feller's Master-Stroke'
10. 'Keep Yourself Alive'
11. 'Drum Solo'
12. 'Keep Yourself Alive (Reprise)'
13. 'Seven Seas of Rhye'
14. 'Modern Times Rock 'n' Roll'
15. 'Jailhouse Rock' / 'Stupid Cupid' / 'Be-Bop-a-Lula' (Medley)
16. 'Liar'
17. 'See What a Fool I've Been'

Disc Two: Nov. 19-20, 1974

1. 'Procession'
2. 'Now I'm Here'
3. 'Ogre Battle'
4. 'Father to Son'
5. 'White Queen (As It Began)'
6. 'Flick of the Wrist'
7. 'In the Lap of the Gods'
8. 'Killer Queen'
9. 'The March of the Black Queen'
10. 'Bring Back That Leroy Brown'
11. 'Son and Daughter'
12. 'Guitar Solo'
13. 'Son and Daughter (Reprise)'
14. 'Keep Yourself Alive'
15. 'Drum Solo'
16. 'Keep Yourself Alive (Reprise)'
17. 'Seven Seas of Rhye'
18. 'Stone Cold Crazy'
19. 'Liar'
20. 'In the Lap of the Gods. . . Revisited'
21. 'Big Spender'
22. 'Modern Times Rock 'n' Roll'
23. 'Jailhouse Rock'
24. 'God Save the Queen'

DVD Bonus Tracks:

1. 'Son and Daughter'
2. 'Guitar Solo'
3. 'Son and Daughter (Reprise)'
4. 'Modern Times Rock 'n' Roll'

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