Marcato in 4 — the basic Argentine tango accompaniment: four heavy, detached beats a bar, chords in the right hand, a walking arpeggio in the left, contrabass doubling it. Scivales writes it as the third rhythmic drill for his tango Salón: Fm6 – G7 – Cm – Cm, right-hand chords mezzo staccato.
How it sits: every beat is marked and equal — no backbeat — but the last beat of each bar is clipped and the next chord is anticipated on the final sixteenth (the a of 4), accented and held into the downbeat. Scivales calls this "the characteristic anticipation of the first beat of the next measure" and says it needs practice. The left hand and bass walk root–third–fifth–third in quarters, detached.
Listen for the weight: short chords, slightly heavier on 1 and 3, and the anticipation landing before the bass changes.
Practice: left hand alone in strict quarters, then add the right hand and make the anticipation the only off-beat event.