Jimmy [Rogers] went out of his way to befriend Sam when he moved to Chicago [in the early 1950s]. So I think that the harmonica style that Sam developed had something to do with the time he spent playing with Jimmy Rogers. He did play some harmonica when he was with Elmore James[. …] He told me that during the sessions he did with Elmore for "Poor Little Angel Child" and "Look on Yonder Wall," where Elmore was playing guitar, Sam played harmonica on several songs that were never released.

Sam developed a unique way to get a very, very fat tone by using the air within his hands cupped together. The way he does this is to turn the amp up a little hotter and then not blow as hard through the harmonica, and use his hands to squeeze the air tighter around the harmonica. That gives it a fatter and fuller sound.

Sam's years of playing trumpet probably influenced his harp playing. A lot of harp players also played other wind instruments like the trumpet or saxophone. If you listen to some of Sam's early work, the way he phrases the harmonica is probably imitative of his phrasing on the trumpet. He uses a lot of short, staccato style phrasing, with no vibrato at the end of the notes. He will use vibrato from time to time, but of all the harmonica players I've heard, he's one who does not rely on a lot of vibrato to end his phrases.