Complex sentence: He claimed that he wrote the song while attending graduate school at LSU, but research indicates he bought it from another performer, Paul Rice, who had recorded it with his brother Hoke, who recorded together as the Rice Brothers under Paul Rice's name.
Split into simpler sentences: He claimed that he wrote the song while attending graduate school at LSU, but research indicates he bought it from another performer, Paul Rice, who had recorded it with his brother Hoke. The two recorded together as the Rice Brothers under Paul Rice's name.