According to the Internet source given below, Weldon Leo "Jack" Teagarden was a jazz trombonist and singer.
Born in Vernon, Texas, his brothers and siste also became professional musicians. His father was an amateur brass band trumpeter and started him on baritone horn; by age seven he had switched to trombone. His first public performances were in movie theaters, where he accompanied his mother, a pianist.
Teagarden's trombone style was largely self-taught, and he developed many unusual alternative positions and novel special effects on the instrument. He is usually considered the most innovative jazz trombone stylist of the pre-bebop era - Pee Wee Russell once called him "the best trombone player in the world" and did much to expand the role of the instrument beyond the old tailgate style role of the early New Orleans brass bands. Chief among his contributions to the language of jazz trombonists was his ability to interject the blues or merely a "blue feeling" into virtually any piece of music.
Personal remarks:
In my vinyl collection I have T for Trombone (Society, SOC 922).

Websites:
	Jack Teagarden	Biography by wikipedia.org.