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Kanye West has performed a selection of new songs in front of a small crowd of employees at Facebook's headquarters, in California [27 July].

In videos posted online the rapper can be seen singing three songs a cappella.

According to hip hop website 2dopeboyz the songs are rumoured to be called Lost In The World, Chain Gang and Mama's Boyfriend.

West can be heard saying: "I got more raps but I don't want to wear out my vocals."

He was rumoured to be at the social network's offices for a meeting about promotion for his new album.

According to reports from staff, the rapper stood on a table in the canteen at lunchtime to air new material.

He blogged about his performance afterwards thanking his canteen audience by saying: "Many times in my life I've had to deal with moments of doubt - your energy was a gift so electric, so genuine, that it really helped me give my best."

The Chicago rapper's forthcoming fifth studio album doesn't have a confirmed title yet but is expected to be released in autumn 2010.

It will be the follow-up to 2008's 808's & Heartbreak - tracks Lost In The World and Chain Gang are both expected to be on it.

West's last UK live appearance came when he joined Jay-Z on stage at this year's Isle Of Wight festival in June for a guest appearance.