House is the most harmonic four-on-the-floor genre, with 7th/9th chord-stabs as its hook

Among four-on-the-floor dance genres, house is singled out as ‘the most harmonic.’ Its defining hook is the chord-stab — short, rhythmic hits of extended chords, classically minor-7 and major-9 organ or piano voicings (chord-extension). A simple chord-progression (ii-V-I, i-VI-III-VII, or a static 2-chord vamp) over a Dorian or natural-minor scale supplies the harmony. This makes house the entry point for a learner wanting to bring harmony into dance music, in direct contrast to techno’s near-atonal, one-chord-or-none approach. Triads alone read as thin here; the 7th and 9th extensions carry the soulful, jazzy house color.

Examples

chord('<Am7 Dm9>').voicing().s('piano').struct('~ x ~ ~') — minor-7 and major-9 stabs hitting on the offbeat.

Assessment

What chord quality plus extensions characterizes the classic house organ/piano stab, and why does that extension choice give house its soulful quality? Name two workhorse house progressions.