This is "Kansas City" from an acetate recorded at the Cavern Club in 1962. Little survives from the Beatles' days at the Cavern apart from photos and paper memorabilia, so far we have only had the recording and film of "Some Other Guy", and a short excerpt of "Kansas City" with voices talking over it on the Anthology DVD-box, so to be able to finally hear the entire Kansas City is sensational! But here it is, from Dailymotion:
The Beatles at The Cavern Club 1962 - Kansas City
The Beatles at The Cavern Club 1962 - Kansas City