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How to play a I-vi-IV-V on the FM-1 with ChoralRoot

ChoralRoot turns the M-VAVE FM-1 into an Orchid-style chord instrument. In its Key Mode a root key on its own plays the chord that belongs on that note of the scale, and with Numerals on, the Chord view writes that chord's Roman numeral above its name. So a I-vi-IV-V in C major is four keys, and the screen numbers each chord as you play it. Shown for ChoralRoot 0.24 (released 2026-10-17); Numerals needs ChoralRoot 0.22 or later.

The short answer

In Key Mode, press C5, A4, F4, then G4.

Before you start

Install ChoralRoot 0.24, then start from its default settings: tap OPT (printed GLO) to open the Options, turn SELECT to the last entry, Reset Settings, and press OCT+ twice. Your saved sounds and loops stay. That leaves Key Mode off, the key on C major, the chord keys on the Classic layout and the screen on the Chord view. Then turn Numerals on: hold KEY (printed SEL) to open the KEY layer, turn SELECT to page 2, turn KNOB 4 to On, and press OCT- to close the layer.

Four steps

Tap KEY, then press C5: C major. The screen shows the numeral I.
0:09
Press A4: A minor. The screen shows vi. Small letters mean a minor third.
0:16
Press F4: F major. The screen shows IV.
0:21
Press G4: G major. The screen shows V.
0:26

I, vi, IV, V. One key each.

Good to know

While Key Mode is on, the root keys glow to show the key: the notes of the scale softly, the tonic brighter. Hold DIM, MIN, MAJ or SUS as you press a root and it overrides the scale's choice of chord type. More on the FM-1 and its firmwares: https://les.audio/guides/m-vave-fm-1. Les is independent and not affiliated with M-VAVE, with ChoralRoot's author or with Telepathic Instruments.

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