There is a specific problem with using music during deep meditation. Music with melody directs attention. It implies narrative. A phrase begins, creates expectation, resolves or doesn't. Part of your awareness follows the music rather than going wherever it was going. This is useful for mood management and concentration. It's counterproductive if you want to get quiet.
The pads channel is an attempt to occupy the space between music and environmental sound. Harmonically alive. Not melodic. Slow enough that the chord changes register as shifts in quality rather than events to track. No beat, no rhythm, no phrase structure the mind can anticipate. Four voices, sustained, crossfading every 20 to 30 seconds into a new chord, cycling through a progression that folds back on itself.
Whether it actually gets out of attention's way depends on the progression, the reverb, how fast the chords change, and probably a few things specific to you. At its best it gives the ear enough texture to release into without giving the mind something to follow.
The progressions
Nine progressions are built in. They fall into three rough groups.
Western modal
Lydian Float is A Lydian: Amaj, Bmaj, C#min, Emaj. The raised fourth (D#) is what makes Lydian sound the way it does — open, slightly unmoored, a brightness that doesn't quite resolve. This is the default for a reason. It pairs well with alpha frequency work and sits high enough in register not to compete with the ocean layer. The crossfade is 5 seconds.
Dorian Drift is D Dorian: Dm, Em, Gmaj, Am. Lower in register, more anchored. The major IV chord (Gmaj) is the Dorian signature — the note that distinguishes it from natural minor. Root for theta work and anything aiming at depth.
Ascending Drone abandons triadic harmony entirely. Four chords built from pure fifths and octaves: C, D, E, G. No thirds, no color tones. The harmonic content is minimal and modal. Good background for sessions where you want the pads to be heard but not felt.
Church / solemn
Phrygian Gate is E Phrygian: Em, Fmaj, Am, Gmaj, Em with Picardy third. The bII movement (the Fmaj chord) is what defines Phrygian and gives it the sacred, slightly ominous quality associated with Gregorian chant and Flamenco both. Five chords, 32 seconds each, long crossfades of 9 seconds. The Picardy close (major third on the tonic) lands like a quiet sunrise.
Aeolian Vespers is A natural minor with a Picardy cadence: Am, Gmaj, Fmaj, Emaj. Descending motion in the bass. The Emaj chord at the end — raised third against the minor tonality — has the function of an evening bell in the sequence. Four chords, 28 seconds each.
Dorian Mass is the longest progression. Six chords over D Dorian: Dm, Em, Fmaj, Gmaj, Am, Cmaj. A full arc through the mode with the bVII chord (Cmaj) opening space before the return. At 32 seconds per chord with 9-second crossfades, one full cycle takes over three minutes. This is a background that can sustain a full 30-minute session without feeling repetitive.
Eastern
Bhairav Morning is C Bhairav, the double-harmonic major scale used in Hindustani classical music as a morning raga. The characteristic sound comes from the b2 (Db) and b6 (Ab) against the major tonic: augmented second intervals that feel ancient and unresolved to Western ears. The C2 drone pedal is baked into every chord intentionally, mirroring the tanpura function. Enable the Pedal Point toggle for the full effect.
Hirajoshi Zen is A Hirajoshi, the Japanese pentatonic associated with koto and Zen aesthetics: A, B, C, E, F. The B–C semitone adjacency in the third chord is the koto character. The final chord leaves E and F a semitone apart at the top — suspended, unresolved, deliberately incomplete. 7-second crossfades.
Maqam Hijaz is D Maqam Hijaz, the Arabic and Ottoman mode heard across North Africa, the Middle East, and Andalusia. The augmented second between Eb and F# is the signature interval: the sound of longing that does not map to anything in the Western diatonic system. The progression passes through a Sufi suspension (G–Bb over a D bass) that offers no resolution. Closes on an Ottoman half-cadence with a suspended seventh. This one has a specific quality of reaching toward something out of range.
Chord timing
Chord duration in the pads channel is not measured in seconds directly. It's measured in beats relative to the current beat frequency.
The Beats per Chord parameter sets how many beats of the entrainment frequency equal one chord duration. At 256 beats per chord and a 10 Hz beat frequency, each chord holds for 256 / 10 = 25.6 seconds. At 6 Hz theta, the same setting gives 256 / 6 = 42.7 seconds.
This means the harmonic rhythm naturally slows with the entrainment frequency. Descend from alpha into theta during a session, and the chords begin to breathe more slowly without any manual adjustment. The pads track the arc.
For very slow progressions — 30 to 45 seconds per chord — high values (512, 1024) work well. At 512 beats and 6 Hz theta, each chord holds for roughly 85 seconds. The changes become events you notice only in retrospect.
Crossfade and articulation
Two articulation modes control how chord changes are delivered.
Sustain is the default. When the chord changes, each voice's envelope ramps down to near silence over half the crossfade time. At the midpoint, the oscillator frequency shifts to the new note. The envelope then ramps back up over the second half. The result is a breath: the sound quietly opens, changes, and returns. With a 6-second crossfade, you have about 3 seconds of fading, a momentary near-silence, then 3 seconds of blooming in. With the reverb on, the tail of the old chord lingers into the first moments of the new one.
Stab replaces the crossfade with a fast 0.8-second attack and an exponential decay. Instead of a sustained chord that holds and then gives way, you get a struck tone that dies on its own. More percussive, less ambient. At lower beat frequencies the stabs arrive slowly and sound like bowls being struck; at faster beat frequencies (if using the Beat Sync feature, covered in Part 6) they become rhythmic. Stab works best with the Bowl tone character on the sacred frequency tiles.
Voice leading
When the chord changes, Sympatheia has to decide which of the four current oscillator pitches moves to which of the four new ones. This is the voice leading problem. There are two algorithms.
Greedy minimizes total pitch movement. Each current voice is matched to the nearest available new note by log-ratio distance (so a jump from 110 Hz to 220 Hz counts the same as from 200 Hz to 400 Hz: one octave). In practice this means the voices tend to hold register across changes, moving by small intervals when possible. The result is smooth, connected, minimal.
Contrary does the opposite. The lowest current voice moves to the highest new note; the highest current voice moves to the lowest new note; voices cross registers. The movement is more dramatic. At slow crossfade speeds with reverb, this crossing sounds organically complex, like singers in a choir passing through each other.
Inversion cycling and palindrome
Two modes modify how the progression moves through its chords over time.
Inversion cycling rotates the lowest note of each chord up an octave on each advance. The first time through the progression, the chords arrive in root position. The second time, they're all in first inversion. Third time, second inversion, and so on. The same sequence of harmonies sounds subtly different each pass through. Over a 30-minute session this creates a slow drift through the same material from different angles without any of it repeating exactly.
Palindrome reverses the direction of the progression at each endpoint. Instead of Chord 1 > 2 > 3 > 4 > 1 > 2 > 3 > 4..., you get 1 > 2 > 3 > 4 > 3 > 2 > 1 > 2 > 3... The progression folds back. Combined with inversion cycling, this means the sequence never quite returns to the same state: same chords, different inversion, traveling in the other direction.
Pedal point
With pedal point enabled, voice 0 (the lowest voice) holds its pitch while voices 1 through 3 cycle normally. The root note of the current chord becomes a continuous held bass beneath everything else.
This changes the harmonic character substantially. In Bhairav Morning, the C2 drone baked into every chord plus an enabled pedal point creates something close to the tanpura function in Indian classical music: a continuous tonic ground that the upper voices move against. In Lydian Float, holding A as a pedal while Bmaj and C#min pass above it creates tensions that wouldn't exist in the plain progression.
The sub oscillator tracks voice 0 when pedal point is active, so the subharmonic stays fixed as well.
Sub oscillator
A sine wave running at exactly half the frequency of voice 0 (one octave below the lowest voice). The sub oscillator is meant to be felt as much as heard. At most useful volume levels it's below 80 Hz, adding physical body to whatever frequency voice 0 is sitting on.
Enable it and keep the gain low. It adds weight to the pads without changing their harmonic character. Run it with headphones and you feel it rather than hear it, which is the point.
Reverb
Four room sizes, all generated algorithmically from exponentially decaying noise.
Room is 1.5 seconds. Barely perceptible. Good for keeping the pads spatially present without blurring them.
Chapel is 3 seconds. The most musically useful for most progressions. Long enough to soften hard edges; short enough to preserve harmonic identity through a chord change.
Cathedral is 6 seconds. With crossfades of 5 to 9 seconds, the reverb tail extends past the next chord change. The old chord bleeds into the new one acoustically. At slow chord rates with Dorian Mass or Phrygian Gate, this sounds like the inside of a stone building. Whether that's useful depends entirely on what you're doing.
Infinite is 10 seconds with a shallower decay. The tone does not die; it sustains and blurs into everything around it. More spatial effect than reverb in the usual sense. Use it with simple, widely-spaced progressions (Ascending Drone, Hirajoshi Zen) where harmonic clarity matters less than texture.
The Space slider controls the wet/dry mix between the dry signal and the convolver output. At 0 the reverb is off entirely; at 1.0 only the wet signal passes. Most useful settings are in the 0.3 to 0.6 range, where the room character is audible but the direct signal still has presence. Push it toward 1.0 with Cathedral or Infinite and the pads lose spatial definition — everything becomes diffuse. That can be the goal, or not.
The pre-delay adds a short gap (0 to 80 ms) before the reverb onset. A little pre-delay gives the initial transient definition before the bloom; the sound source seems closer even as the reverb suggests a larger space. At zero the bloom starts immediately and the pads feel more submerged. The default is 25 ms, which is perceptible on headphones and mostly imperceptible on speakers.
Filter
A lowpass filter sits in the signal path between the voices and the reverb. The cutoff slider controls where the filter rolls off high-frequency content. At the default (3600 Hz) the pads have their full harmonic character. Roll it down toward 400–600 Hz and the sound becomes darker, more muffled — useful for sessions aimed at delta or deep sleep where brightness would be intrusive.
The Filter Env toggle adds a per-chord sweep. Each time a chord changes, the filter starts at roughly 15% of the target cutoff and ramps exponentially up to it over the crossfade time. The chord arrives dark and opens over several seconds into its full register. In sustain mode the sweep tracks the crossfade duration; in stab mode it tracks the stab attack. The effect is similar to a slow vowel opening on each chord change — subtle at long crossfade times, more noticeable on shorter ones.
Filter env is most effective with progressions that have harmonic brightness to reveal. Lydian Float and Phrygian Gate open noticeably. On Ascending Drone with its pure fifths, the sweep is barely perceptible.
Tremolo and Beat Sync
The tremolo LFO modulates the overall pads amplitude at a set rate and depth. At low depth (0.04 to 0.08) the pads breathe slowly. At higher depth the amplitude variation becomes clearly audible.
The rate can be set freely, or it can be locked to the current beat frequency via the Beat Sync button. When Beat Sync is active, the tremolo oscillates at exactly the same frequency as the entrainment beat. The pads' harmonic texture begins pulsing at the target state. Part 6 covers why this matters from a neural entrainment standpoint.
How I use this
The pads channel was added to Sympatheia later than the other layers, and I'm still finding what works for me. A few things have settled.
For theta work, Dorian Drift or Dorian Mass with cathedral reverb, palindrome on, beats per chord at 512. The Dorian quality — minor with a raised sixth, that note that doesn't quite belong — creates an open, slightly questioning atmosphere that suits the theta hypnagogic territory. The progression never fully arrives anywhere.
For longer sessions where I want the pads to be present but not noticed, Ascending Drone with room reverb and a high beats-per-chord value. The fifths-only harmonic content recedes into the background quickly.
The Eastern progressions are interesting and I haven't fully explored them yet. Bhairav Morning with pedal point enabled and a slow crossfade is the most compelling of the three. The augmented second intervals require some time to become familiar before they stop pulling attention. Once they do, there's something there.
The pads are off more often than on in my practice. When they're on, they're quiet, placed in the left channel slightly, a texture beneath the ocean and the entrainment signal rather than a feature.
What's next
Part 6 covers what happens when the tremolo sync is activated and why pulsing amplitude at the entrainment frequency is a more direct path to brainwave entrainment than the binaural beat mechanism — and how to build sessions that don't require headphones at all.