Shout — the fast praise-break groove of the Black Pentecostal church (and, through it, of rock and roll): a driving shuffle where the piano's left hand plays walking octaves in quarters (root–3rd, root–3rd of the next chord, 5th–3rd, 5th–7th) and the right hand hammers the chord on 2 and 4 with a short swung pickup on the "and" after each. The kit is four on the floor with a heavy snare backbeat, a shuffle hat and a double snare on the swung "and" of 4 — the drummer turning every bar around. The bass doubles the octaves.
Two bars of I–IV / I–V7 is the shout "stuck" on a vamp; real shouts modulate up and get faster.
Listen for the backbeat chords as the thing people clap — in church the whole room is on 2 and 4 — while the octaves and the kick keep all four beats underneath. Compare boogie-woogie-lh and shuffle-blues, where the same left-hand idea is a blues instead of a praise break, and stride-lh for the chord-on-2-and-4 ancestor.
Practice: left hand alone with the kick, octaves even and loud; then chords on 2 and 4 only; add the "and" pickups last, lighter than the backbeat.