Amos Leon Thomas, Jr. (October 4, 1937 – May 8, 1999) was an American avant-garde jazz singer from East St. Louis, Illinois. 　　Thomas studied music at Tennessee State University. In the 1960s he was a vocalist for Count Basie, among others. 　　In 1969, he released his first solo album for Bob Thiele's Flying Dutchman label. However he made an earlier album that remains unreleased. Thomas is best known for his work with Pharoah Sanders, particularly the 1969 song "The Creator Has a Master Plan" from Sanders' Karma album. Thomas's most distinctive device was that he often broke out into yodeling in the middle of a vocal. This style has influenced singers James Moody, Tim Buckley and Bobby McFerrin, among others. He said in an interview that he developed this style after he fell and broke his teeth before an important show. Some of the vocal style is classified as 'jive singing'. (Ref: Leon Thomas Blues Band album). 　　Thomas toured and recorded as a member of the band Santana in 1973. He changed his name to Leone in 1974 because of an interest he had in numerology at the time. He did not legally change his name and he reverted to Leon shortly thereafter. 　　Thomas died of heart failure on May 8, 1999. He was largely forgotten until a resurgence of interest in soul jazz. Several of his tracks have been sampled in hip-hop and downtempo records.