Ambient harmony uses drone or pedal-tone beds with unresolved extended chords
Rather than harmonic progression, ambient music sustains a drone or pedal-tone foundation and layers extended chords (maj7/9/add9, sus voicings) that deliberately avoid resolving. The goal is stasis with color: the harmony supports the timbral and spatial experience without introducing forward motion. Voice leading between chords, when it happens, should be maximally smooth — chords melt into each other. Lydian or major modes give a bright/dreamy character; minor or Dorian give melancholy.
Examples
A Strudel patch: drone on C, slow chord cycling through Cmaj9 → Fmaj9 with .legato(4) and .attack(2), Lydian mode. No rhythm, no clear cadence.
Assessment
Compose a 4-chord ambient harmonic sequence; for each chord name one reason it avoids resolution, and explain why sus/add9 voicings suit the genre.