If Christina Aguilera's hit "Ain't No Other Man" sounds like a classic, that's because its infectious beat comes from a 43-year-old song -- and a new lawsuit claims Sony Music hasn't paid the rightful owner for the sample.
Take a listen ... Christina's song clearly samples from a 1968 latin soul tune called "Hippy Skippy Moon Strut" (aka "I'll Be a Lucky Man) by Dave Cortez and the Moon People. Gotta love that name.

According to the federal lawsuit, filed in New York, TufAmerica purchased exclusive rights to 'Hippy Skippy' in 2004 ... however Sony Music -- Christina's label -- made a deal with Codigo Music and the Clyde Otis Music Group to use the song.

TufAmerica is asking the court to declare it the rightful owner of the groovy '60s hit ... and to void the other publishers' claims on the song. The company also wants damages -- as in money.





Read More: Tmz