David Thomas Mason is an English singer-songwriter and guitarist from Worcester, who came to prominence in 1967 as a founding member of the rock band Traffic. While with Traffic, he wrote and sang lead vocals on two of the band's most famous songs, "Hole in My Shoe" and "Feelin' Alright?". His song "Only You Know and I Know" became a signature song for Delaney & Bonnie, and "We Just Disagree", Mason's 1977 solo U.S. hit, written by Jim Krueger, has become a staple of U.S. classic hits and adult contemporary radio playlists.