Study Tom Turpin’s Harlem Rag (1897) in C, in 2/4. From bar 5 the left hand plays the ragtime bass, a low note on each beat and a chord off the beat: keep its leaps light and exact, and the right hand’s syncopations even above it. The stride bass of the 1920s grew out of this pattern, with wider leaps and faster tempos; the stride card prepares it. At the keyboard: play a stride bass and a twelve-bar blues.