This improvisation proceeds in a slow, reflective and searching style — an exploration of two contrasting modes that share F as a tonal centre but diverge slightly in colour and temperature. The piece alternates between the shadowed gravity of F Phrygian and the amber warmth of F Mixolydian ♭6, and then finally resolving into a quiet Tierce de Picardy — a momentary turn from minor to major light.

Modal palette

Mode	Parent scale	Formula (T = tone, S = semitone)	Notes used	Character
F Phrygian	D♭ major (3rd mode)	S – T – T – T – S – T – T	F – G♭ – A♭ – B♭ – C – D♭ – E♭ – F	Dark, enclosed, ancient
F Mixolydian ♭6	B♭ melodic minor (5th mode)	T – T – S – T – S – T – T	F – G – A – B♭ – C – D♭ – E♭ – F	Warm yet unsettled, bittersweet

The shared flattened 6th (D♭) gives both modes a sense of shadow, while their different 2nd degrees — G♭ vs G natural — create a dialogue between tension and release. The flattened 2nd of the Phrygian pulls the darkness down further. The major 3rd of the F Mixolydian ♭6 creates a warm glow.

Learn more about the Mixolydian ♭6 mode and the Phrygian mode, including note names for all 12 keys.

Texture and phrasing

The left hand has a varied broken-chord and arpeggiated pattern, with a gentle pulse. The right hand weaves between single-line melodies, harmonic intervals (3rds, 6ths), and occasional triadic shapes.

Mood and atmosphere

Due to the specific combination of modes, pulse and texture, the overall mood is slow, pensive, and quiet — like standing between two kinds of darkness: one earthy and inward (Phrygian), one glowing faintly with residual warmth (Mixolydian ♭6).

The closing Tierce de Picardy — an F major chord emerging from F minor — feels less like resolution and more like a brief lifting of the veil.

Stylistic lineage

The modal pairing of F Phrygian and F Mixolydian ♭6 carries faint echoes of both Renaissance counterpoint and English folk modality. The Phrygian inflections and the Tierce de Picardy recall the harmonic language of early sacred music. The Mixolydian warmth and flattened sixth appear in the luminous pastoral world of composers like Vaughan Williams — where ancient modes were reimagined through modern harmony and lyricism.

Tierce de Picardy

The Tierce de Picardy — literally “Picardy third” — refers to the common Renaissance and Baroque practice of ending a minor-key piece with a major tonic chord. By raising the third of the final chord, composers created a momentary sense of radiance and resolution. As this improvisation is predominantly in F Phrygian — a mode sharing the same minor inflection as F minor; the F major chord at the end creates the Tierce de Picardy.

The tritone

The melodic motif of C to G♭ — a tritone once known in medieval theory as the “devil’s interval” — recurs throughout this piece. It was a motif that felt right to me as I was playing it. In the context of F Phrygian, it feels less diabolical than inevitable: the natural tension at the heart of the mode’s sound, dark and strangely luminous in equal measure. It emphasises one of Phrygian’s essential colours — that semitone between the 1st and 2nd degree, expanded into a tritone against the dominant. This is a nod to the spirit of the Renaissance, and of the English pastoral-modern lineage that transformed those modal dissonances into emotional poetry.

Listen

You can learn more about modes here: Complete Guide to Modes of the Major, Melodic Minor, and Harmonic Minor Scales

To hear to a faster improvisation listen to Nocturne in F Dorian – A Modal Improvisation, with Db Lydian and F Phrygian

For an improvisation exploring a different combination of modes listen to Ionian Ghosts – Improvisation in C Dorian, A Phrygian, Ab Ionian and Ab Lydian

Here is another improvisation using the Mixolydian flat 6 mode: Threshold in D – Piano Improvisation Through Shifting Modes