Katy Perry has revealed the tracklisting for her forthcoming new album.

The singer is unleashing 'Prism' on October 21 in the UK and a day later in the US.

A number of the record's song titles have already been made public, but the official tracklisting for the album has now been issued - check it out below.

Perry meanwhile rounded off the iTunes Festival in London last night (September 30), where she played some new tracks - such as 'By the Grace of God' - as well as her hits.

The full tracklisting for 'Prism' meanwhile is as follows:

• 1. Roar
• 2. Legendary Lovers
• 3. Birthday
• 4. Walking On Air
• 5. Unconditionally
• 6. Dark Horse (feat. Juicy J)
• 7. This Is How We Do
• 8. International Smile
• 9. Ghost
• 10. Love Me
• 11. This Moment
• 12. Double Rainbow
• 13. By the Grace of God