Katy Perry has announced her new album 'PRISM' will be released on October 22, 2013.
The 28-year-old singer enlisted the help of a huge golden truck with ''KATY PERRY - PRISM - 10-22-13'' emblazoned on the sides and the rear in big black writing to promote the title and release date of her fourth studio album.

The 'Firework' hitmaker took to Twitter to encourage people to look out for the vehicle as it drove around Los Angeles yesterday (29.07.13), and several stars spotted the large lorry including 31-year-old singer Adam Lambert, who took a picture of the ''crazy'' stunt and posted it on the social networking site.
In a message accompanying the image, he wrote: ''Yes @katyperry this is crazy!! Love it!
''#PRISM (sic)''

Earlier in the day, Katy promised to retweet anyone who posted a picture of her 'PRISM' truck, and reassured her legions of fans - who are known as Katykats - the lorry will be visiting other locations around the country.
She wrote: ''Find the #PRISM semi, take a picture and I'll RT you. Don't worry, Los Angeles is just the first stop on the map. (sic)''

'PRISM' will be a follow up to 2010's 'Teenage Dream', which made history after becoming only the second album ever - after Michael Jackson's 'Bad' - to spawn five number one singles from the same record on the Billboard Hot 100 chart in the US.
The brunette beauty also became the first female to achieve such a milestone.