In the fifties the blues in Chicago was especially about the electric guitar and the harmonica and all of that especially on the label Chess. The piano and the saxophones had a rough deal. So today piano player Willie Mabon (1925-1985) who created a unique sound.
Sources:
Willie Mabon – Blues Roots vol.16 (Chess lp 6.24806)
Willie Mabon – Cold Chilly Woman (Black and Blue 33.501)