The chord track and harmony

The chord track is a lane under the ruler that holds the song's chords: Am for two bars, then F, then C. You can write chords by hand, have Nebula find them in your MIDI or audio, and turn them back into notes. Other parts of Nebula read it too.

Show the chord track

The chord track is one of the global tracks, the lanes under the ruler.

  • Choose Track ▸ Show or Hide Global Tracks (G) to show or hide them.
  • Choose Track ▸ Configure Global Tracks and turn on Chord. The same menu turns the Arrangement, Marker, Tempo, Signature and Tape Stops lanes on and off.

The chord lane's header reads CHORDS. Its round menu button holds Detect from MIDI, Detect from Audio, Create MIDI from Chords and Clear Chords.

Write chords

  1. Drag along the chord lane where the chord should be. It snaps to the arrangement's grid.
  2. Nebula suggests a chord: what the MIDI under it plays most, or the key's first chord when nothing plays there.
  3. Double-click the chord to change it. Type any chord in the field (for example Am7 or G/B) and press Return, or click one of the key's own chords below it.

Nebula reads chord symbols such as C, Am, F#m7b5, Bbmaj7, G/B, Csus4, E7, Ddim, Caug, C6 and Cadd9, and spells them in the key that plays there: Bb in F major, A# in B major.

  • Drag a chord to move it, or drag its left or right edge to change its length. A chord replaces whatever chords it lands on.
  • Click a chord to select it. Shift-click selects every chord from the last one clicked; Command-click adds or takes one away.
  • Right-click a chord and choose Delete Chord, or Delete in its editor.

Every change to the chord track is one undo step.

Detect chords from MIDI or audio

Choose Track ▸ Chords ▸ Detect Chords from MIDI. Nebula reads the notes on instrument tracks and writes the chords it finds. Drum tracks, audio tracks and muted tracks are left out. It is exact for MIDI.

Choose Track ▸ Chords ▸ Detect Chords from Audio to read chords from recorded sound. Nebula renders the audio as you hear it, through its plug-ins, and reads it beat by beat. It reads the audio regions you have selected, or else every unmuted audio region on tracks that are not drums by name.

Both act on the cycle when it is on, and on the whole song otherwise, and replace the chords already there. If nothing is found, Nebula says why.

Turn chords into MIDI

  • Track ▸ Chords ▸ Select All Chords selects every chord on the track.
  • Track ▸ Chords ▸ Place Selected Chords on a New MIDI Track puts the selected chords on a new instrument track called Chords, as one MIDI region. Right-click a chord for the same.
  • Drag chords down out of the lane and let go on an instrument or bass track: they land there as a MIDI region, at the beat under the pointer. Let go anywhere else and they go on a new track.
  • Track ▸ Chords ▸ Create MIDI from Chords makes a new instrument track, Chords, that plays the whole chord track: each chord held for its length, with its bass note below.

Clear chords

Track ▸ Chords ▸ Clear Chords takes the chords away: inside the cycle when it is on, from the whole song otherwise.

The song's key and key changes

The song's key is set in the transport bar, beside the tempo. To change key partway through, show the Signature global track and double-click it at the bar where the new key starts, then choose Key, Major or Minor, and the key. Click a key in the lane to change it, or choose Delete Key Change.

The chord editor offers the chords of the key that plays where the chord is.

What uses the chord track

  • The Transposer MIDI effect can hold notes to a scale. Song Scale follows the song's key; Chord Track follows the chord at each note, and the song's scale where there is no chord.
  • The Arpeggiator's Source can be Chord Track: it plays the song's own chords, no keys needed. Idle: Chords plays them only while you are not playing keys.
  • The Chord Trigger's root can follow the song's key.
  • A track set to Follow Chords plays its regions on the chords (see below).
  • Nebula Delay and Nebula Cosmos follow the chord track: where a chord sounds, they use its notes; between chords, their own key and scale lead again.
  • When Claude compares your takes, it measures pitch against the song's key, and against the chord track's chord where one sounds.

Parts that follow the chords

A track's regions can follow the chord track, as Cubase's chord track and Studio One's harmonic editing do. Change a chord, or move a region under another one, and the part plays the new chords. The notes stay as you wrote them: you hear them moved, and Off gives back exactly what you wrote.

Select the track and, in the inspector's track section, set Follow Chords, or choose Track ▸ Follow Chords (each choice can have a key in the Key Commands window):

  • Off: the notes play as written.
  • Chords: every note moves to the nearest note of the chord where it sounds. Use it for pads, stabs and comping. Under F, an E becomes an F.
  • Scale: notes move only where the chord's scale differs from the key's. Under Cm in C major, an E becomes E♭. A passing note outside the key, such as a C♯ between C and D, stays as you wrote it.
  • Bass: the lowest note under each chord moves to its bass note (the slash note when the chord has one), and the rest of the line moves with it, kept in the chord's scale.

A note played a thirty-second before a chord belongs to that chord. Where there is no chord, the notes play as written. A loop plays each repetition under its own chord. Region Transpose is applied before the follow, so the part still lands on the chords.

Instrument, bass and audio tracks can follow; drum tracks never move. On an audio track the follow works through Flex Pitch: Nebula finds the notes of the voice and moves each one, so use it on a single voice (a vocal, a bass, a lead line), not on chords. It acts on regions that play forward and do not loop, as Flex Pitch does. Your own Flex Pitch edits stay and play on top.

The piano roll shows the notes as written. A track that follows the chords is left out when Nebula detects chords from MIDI, because it is led by the chord track.

Changing the mode is one undo step, for every chosen track.

Claude and chords

Claude can read the chord track, write a progression on it, detect chords from your MIDI or audio, make a MIDI track from the chords, and set the song's key. Ask it, for example, to write Am F C G over bars 1 to 8. It can also set how a track follows the chords, for example "make the pad follow the chords".