Previously undiscovered tapes of late American blues and soul legend Ray Charles, found in a vault in California, will be released in Britain in October.

Ray Sings, Basie Swings is tipped to be one of the bestselling jazz records of the year. With the aid of technology it mixes Charles's vocals with newly recorded music by the Count Basie Orchestra. John Burk, A&R chief of jazz label Concord Records, stumbled on the lost tapes late last year while rummaging through the label's vaults in Berkeley.

The tapes were marked "Ray/Basie", giving rise to hopes that they were the first collaboration between Charles and the orchestra of legendary bandleader. But when it was discovered that Charles and the orchestra had played different sets during the recordings — for legendary producer Norman Grantz — Charles's original vocals were kept, with the current Basie Orchestra re-recording the music.

Burk said: "The quality of these reels wasn't great. They appeared to be recordings from the live soundboard with Rays vocal upfront, the band way in the background. But Ray sounded amazing.

"The end result is a beautiful, authentic and irreplaceable piece of music. We can help Ray do what he always did so naturally — make magic happen."

Charles, who died in 2004 aged 73, was born a penniless orphan in Georgia and went blind aged seven. His life was made into a Hollywood movie in 2004.