Sir Paul McCartney and Ringo Starr appeared on stage for the first public viewing of Beatles Rock Band. The karaoke-style game lets users use adapted game controllers - lead guitar, bass guitar and drums - to play along to various songs. Yoko Ono and George Harrisons widow, Olivia also attended the premiere of the Harmonix title. The game marks the first time any Beatles music has been licensed to a third party. The game is good, the graphics are very good, and we were great, said Ringo. The game, which goes on sale on 9 September, will feature 45 songs, along with a bonus track - All You Need is Love - which can be bought online via Xbox Live. Microsoft says all proceeds from the sale of the bonus song will go to Doctors Without Borders, the US branch of the charity Medecins Sans Frontieres (MSF). Sir Paul McCartney was enthusiastic. We love the game, its fantastic, he said. Beatles Rock Band takes players to a number of locations where The Beatles played, including the Cavern Club in Liverpool and New Yorks Shea Stadium. There are cut sequences between songs that, say the developers, are artistic visual expressions intended to transport players to the imaginative environments that capture the essence of The Beatles musical and fashion transformations during their later years. A scrolling screen displays various coloured notes, which players have to match to a musical key on their instrument. -BBC Get it right and the musical note is played, miss the beat and the music goes wrong. Get it wrong enough times and players will be booed off stage. The games musical instruments are based on the ones The Beatles played in the 1960s and there are 3D models of all the Fab Four playing their instruments, in a variety of costumes, within the game. Whoever thought we would end up as androids? said Sir Paul. Ms Ono and Ms Harrison also made an appearance, coming out to wave to the audience but leaving the stage before Sir Paul and Ringo appeared. -BBC