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Helix Simple Pitch

Helix Simple Pitch integration lets Praxis automatically retune your instrument path per song by sending MIDI CC to a Line 6 Helix preset that contains a Sim...

Helix Simple Pitch

Helix Simple Pitch integration lets Praxis automatically retune your instrument path per song by sending MIDI CC to a Line 6 Helix preset that contains a Simple Pitch block.

Why This Exists

When a recording is not exactly at A440, you generally have two options:

  • Tune the song to your instrument (keep instrument at A440, retune audio).
  • Tune your instrument to the song (leave audio as-is, retune your signal path).

Helix Simple Pitch is for the second workflow. Praxis reads each song’s tuned offset and sends the appropriate MIDI so your Helix shifts pitch automatically when the song loads.

What The Song's tuned Value Means

Praxis uses the song's tuned field as a pitch offset in semitones, including fractional values.

Examples:

  • 0 means no correction is needed.
  • -0.32 means the song sits about 32 cents flat, so Praxis should shift your live signal down by about 32 cents.
  • +1.00 means shift up one semitone.
  • -2.14 means shift down two semitones plus about 14 cents.

This value is about matching your live instrument signal to the recording. It is not the same thing as changing the playback pitch of the song itself.

What Praxis Controls

Praxis drives three Helix Simple Pitch parameters via CC:

  • Bypass CC (example: CC40)
  • Interval CC (example: CC41)
  • Cents CC (example: CC42)

These are exactly the values you configure in Settings > MIDI > Helix Simple Pitch.

At runtime:

  • if tuned is 0, Praxis sends Bypass 0 so the Simple Pitch block is bypassed
  • if tuned is non-zero, Praxis sends Bypass 127 and then sends Interval and Cents values that match the song

Praxis splits the song tuning into:

  • a whole-semitone interval
  • a cents offset between -50 and +50

That matches how Helix Simple Pitch expects to be driven.

Helix Setup (Hardware/Preset)

  1. Create or open the Helix preset you want to use for Praxis playback.
  2. Add a Simple Pitch block in your signal chain.
  3. In Helix, assign MIDI CC to: Bypass, Interval, and Cents parameters of that block.
  4. Use your desired CC numbers (example set: Bypass=40, Interval=41, Cents=42).
  5. Set Helix MIDI receive channel to match the channel Praxis will send on.
  6. Save the preset after MIDI assignments are confirmed.

Praxis Setup

  1. Open Settings > MIDI.
  2. Enable Helix Simple Pitch.
  3. Set Helix Send Channel to either: Default (uses MIDI Default Send Channel) or a fixed channel.
  4. Set: Bypass CC = 40, Interval CC = 41, Cents CC = 42 (or your own values).
  5. Ensure your song metadata includes a tuned value where needed.

How It Behaves at Runtime

  • When a song loads, Praxis reads its tuned offset.
  • Praxis sends Helix CC to enable/bypass and set Interval/Cents as needed.
  • If tuned offset is neutral (0), Praxis bypasses the Simple Pitch block.
  • This happens per-song, so you can move through a mixed tuning setlist quickly.
  • If Helix Simple Pitch is enabled but a song has no valid tuned value, Praxis does not have a meaningful correction to send for that song.

Automatic Vs Manual Control

Praxis supports two related Helix workflows:

  • Automatic per-song correction using the song's tuned field
  • Manual live adjustment from the Helix control panel in the player or from Praxis Remote

The automatic path is what most setlists need. Manual controls are useful when you want to nudge the current setting up/down in rehearsal without editing song metadata first.

If you want consistent automatic behavior across a setlist, keep the song tuned values accurate and let Praxis send Helix updates on song load.

Practical Workflow Example

Suppose your instrument is standard A440, but one track is slightly flat relative to A440. Instead of retuning the audio file, you store the offset in Praxis and let Helix Simple Pitch shift your signal to match that track while you play along.

Next song may be perfectly in tune at A440; Praxis loads it and sends updated MIDI so Helix returns to a neutral state. This lets you practice across mixed-source recordings without manually editing every preset.

Verification Checklist

  • Helix preset contains Simple Pitch block.
  • Bypass/Interval/Cents MIDI assignments exist in Helix.
  • Praxis CC values match Helix assignments (for example 40/41/42).
  • MIDI send channel matches Helix receive channel.
  • Praxis can send MIDI (verify with Test MIDI in settings if needed).
  • Song has a tuned value that should produce audible pitch adjustment.
  • A song with tuned = 0 bypasses the block instead of forcing a pitch shift.

Troubleshooting

  • No pitch change: verify channel match and CC assignments on both sides.
  • Wrong amount of shift: verify the song's tuned value is stored in semitones, not raw cents or Hz.
  • Helix turns on but sounds neutral: confirm the song isn't set to 0 or rounded close enough to zero to bypass.
  • Inconsistent behavior across songs: verify each song’s tuned metadata is set correctly.
  • No MIDI response at all: use Test MIDI to confirm output path and Helix MIDI input state.