ChordBud 2 helps you design chord progressions quickly, edit each chord in detail, and sequence the result to your favorite synths, samplers, or host tracks. It is primarily a MIDI sequencer: the generated notes are sent as MIDI, while the standalone app also includes an optional built-in sampler so you can monitor ideas directly.
ChordBud 2 is available as:
ChordBud 2 separates chord choice from chord placement.
The lower chord grid shows chords generated from the current Key, selected scale rows, and selected Chord Progression. Tap a chord to place it into the timeline. The timeline then controls when the chord plays and how long it lasts. Select a timeline chord to open the chord edit panel, where you can change its chord color, octave, inversion, velocity, duration split, or individual key.
Each timeline chord is converted to MIDI notes at playback time. The chord's stored root, chord type, modifier, inversion, octave, duration, and velocity determine the MIDI note events that ChordBud 2 sends.
The home screen lets you create, open, and play through saved projects.
Projects are saved on the device when you leave the project screen or when the app terminates. A new project starts with one empty pattern, key C, 120 BPM, MIDI input channel 1, MIDI output channel 1, pattern CC 10, Add to Next chord input behavior, and Trim Overlaps timeline resolution.
The project screen has four main areas.
| Area | What It Does |
|---|---|
| Play/Stop | Starts or stops the standalone transport. In the AUv3 plugin, the host transport controls playback. |
| Timeline | Shows the current pattern's arranged chords. Drag chords to move them or drag the right edge to change duration. |
| Chord Edit | Appears when a timeline chord is selected. Use it to change chord modifiers, velocity, octave, inversion, split, transpose, preview, or delete. |
| Chord Grid | Shows chord choices by scale row and progression column. Tap a chord to add, append, or replace according to the chord input setting. |
| Bottom Toolbar | Contains Key, Patterns, Undo, Clear, Randomize, and Settings for the current sequencer pattern. |
| Side Settings Menu | In the standalone app, opens from the top settings button and controls tempo, sampler, Ableton Link, MIDI ports, and support actions. |
When you tap a chord, ChordBud 2 creates a one-bar chord item by default. The timeline range grows to fit the furthest chord and rounds the loop end up to a whole bar.
The dice button in the bottom toolbar gives you a complete chord progression in a single tap, instead of building one chord by chord.
Each tap picks a musical feel — think along the lines of a bright pop groove, a laid-back jazzy comp, or a cinematic minor mood — and generates a fitting key, chord progression, and rhythm to match, filling out the current pattern's timeline immediately. The chord grid's key and progression settings update to match what was generated, so everything stays in sync and ready to play.
A few things worth knowing:
Use the randomizer to kick-start a new pattern, break out of a writing block, or just explore chord and rhythm ideas you might not have reached for on your own.
The groove the randomizer builds is shaped across the whole phrase rather than just tiling one repeating shape bar after bar:
Which of these show up, and how strongly, depends on the musical feel that got picked for that tap, same as the chords and key — so tapping the dice again can give you a noticeably different rhythmic personality as well as a different progression.
The timeline is the arrangement surface for the current pattern.
ChordBud 2 keeps the loop length from shrinking automatically. If you add a chord past the current loop end, the loop grows. If you remove or shorten chords, the existing loop length is preserved until you change it.
While playing, the timeline automatically scrolls to keep the playhead centered, similar to a DAW timeline view. Playhead following pauses as soon as you:
This keeps the view still while you are deliberately looking at something, instead of being pulled away mid-edit or mid-scroll.
Following picks back up on its own, without waiting for the next play, once you release a manual scroll or close the chord edit panel — as long as the playhead is still on-screen ahead of where you scrolled to (it has not yet caught up to the middle of the timeline). If you scrolled backward to review chords that already played, following stays off until you press Play again. It always re-engages on the next transport start regardless.
Tap a timeline chord to open the chord edit panel.
The horizontal modifier row changes the selected chord's color while preserving its root and base harmonic function where applicable.
Available modifiers include Triad, sus2, sus4, add9, add11, add13, dim, aug, 6, 7, M7, 7b5, half-diminished 7, M7b5, 7#5, M7#5, diminished 7, 7b9, 7#9, 7b5b9, 7b5#9, 7#5b9, 7#5#9, 9, M9, 6/9, 7sus2, 7sus4, M7sus2, M7sus4, 11, 9#11, 9b11, M11, 13, and M13.
Velocity, Octave, and Inversion are each set with a vertical fader. Drag a fader to preview its value live; the chord updates once you release.
Velocity sets the MIDI note-on velocity for the selected chord from 0 to 127. New chords default to velocity 90.
Octave transposes the selected chord's generated notes by octave. New chords default to octave 3. The fader covers octave values from -1 through 8.
Inversion changes the chord inversion. The available maximum depends on how many notes the current chord contains, so larger extended chords expose more inversion positions than simple triads.
The bottom Key control changes the key used by the chord grid. Changing the project key updates the chord choices immediately. By default it does not rewrite chords already placed in the timeline — enable Transpose On Key Change in sequencer settings if you want it to.
Open the bottom-toolbar Settings button to edit the current pattern's musical source:
Chord input behavior options:
| Option | Behavior |
|---|---|
| Add to Next | Adds the chord immediately after the selected timeline chord. If no chord is selected, it falls back to adding after the latest chord in the pattern. After insertion, ChordBud 2 checks the whole timeline and resolves overlaps using the When chords overlap setting. The new chord becomes selected. |
| Add to End | Adds the chord at the current range head position. If a chord was selected, the new chord becomes selected. |
| Replace | Replaces the selected chord's root and chord type. If no chord is selected, it inserts a new chord after the latest chord. |
When adding, moving, or resizing chords in the middle of a pattern, ChordBud 2 checks the timeline and applies the selected overlap behavior. The same setting governs both inserting a chord from the grid and editing a chord directly on the timeline, though the two act slightly differently — inserting always needs to make room for a whole new chord, while dragging or resizing only needs to clear whatever it now touches.
| Setting | Behavior |
|---|---|
| Trim Overlaps | Default. The chord you just placed, dragged, or resized keeps its exact position and length. Any chord it overlaps is shortened; a chord it lands strictly inside of is split in two so the piece after it survives as a new chord instead of being lost; a chord it fully covers is removed entirely. |
| Shift Overlaps | The chord you just placed, dragged, or resized keeps its exact position and length, and nothing is ever shortened, split, or removed. Inserting a chord from the grid always pushes every later chord forward by its full duration, even across an existing rest. Dragging or resizing a chord on the timeline only pushes chords it actually now overlaps — growing a chord by dragging its right edge pushes later chords forward by the same amount, but moving a chord, or shrinking it, only pushes what it collides with and never disturbs a rest further down the timeline. |
Patterns are independent chord sequences inside the same project. The toolbar shows numbered pattern buttons and a + button.
You can create as many patterns as you need. MIDI CC and AU parameter automation can switch patterns during playback. See Pattern Chaining to have ChordBud 2 switch patterns for you automatically.
Pattern Chaining automatically switches between patterns as you play, instead of waiting for a manual switch or MIDI CC message. It lives in the sequencer Settings sheet, right below the pattern controls.
Turn on Pattern Chaining to reveal a Mode picker with three options:
| Mode | Behavior |
|---|---|
| Next | Plays through patterns in order, looping back to the first after the last. |
| Random | Jumps to a random pattern other than the one currently playing. |
| Custom | Plays a chain you build yourself, with its own pattern order and per-step repeat counts. |
Next and Random share one Repeat Count setting (1 to 100) — how many full pattern cycles play before the chain moves to the next pattern. Custom replaces that setting with an Edit Chain button that opens the chain editor.
The chain editor lists one step at a time. Each step has:
Tap + in the navigation bar to add a new step. Each new step defaults to the pattern right after the last step's, so building a chain that walks through every pattern once is just a few taps of +.
A custom chain is only as valid as the patterns it points to. Deleting a pattern that a chain step refers to does not rewrite the chain — that step is simply skipped during playback, and the chain editor still shows it. If you re-add the missing pattern later, the step starts working again exactly as authored. Adding, deleting, or reordering patterns never edits an existing custom chain for you.
Selecting a pattern by hand — tapping a pattern button, sending a Pattern MIDI CC message, or automating the Pattern AU parameter — always takes priority over the chain. After a manual switch, the chain resumes from its first step the next time it advances, rather than continuing from wherever it left off.
Stopping playback also resets the chain to its first step, so every new take starts the chain from the top.
In the standalone app, the play button toggles between play and stop. Tempo is set in the side settings menu.
In the AUv3 plugin, the host transport controls playback. ChordBud 2 follows the host's musical context and uses the host beat position and tempo while rendering MIDI output.
ChordBud 2 sends MIDI notes generated from the timeline and accepts MIDI input for pattern switching and held-note tracking.
The standalone app creates virtual CoreMIDI ports by default:
The side settings menu lets you enable or disable virtual MIDI ports and toggle detected external MIDI inputs and outputs. MIDI Bluetooth opens the system Bluetooth MIDI browser.
Generated MIDI is sent to all available destination UIDs and the active virtual output ports. The app also feeds the same generated MIDI to the built-in sampler when the sampler is enabled.
The sequencer settings sheet contains:
Incoming notes and CC messages are accepted only when they match the selected MIDI input channel. Outgoing sequencer and preview notes use the selected MIDI output channel.
Pattern MIDI CC# sets the controller number used for pattern switching. Default is CC 10. The range is 0 through 127.
When ChordBud 2 receives the configured CC on the selected MIDI input channel with a value greater than 0, it selects pattern number equal to the CC value. For example, with the default CC 10, a value of 1 selects pattern 1, value 2 selects pattern 2, and so on. Values outside the available pattern count are ignored.
MIDI Panic! sends note-off messages for every MIDI note number from 0 through 127 on the current MIDI output channel. Use it if an external synth or host track keeps sounding after routing or transport changes.
The standalone app includes a sampler for monitoring ChordBud 2 without another instrument app.
Sampler settings are in the side settings menu:
The sampler is for local monitoring inside the standalone app. ChordBud 2 still sends MIDI out while the sampler is enabled, so you can hear the internal sound and drive external apps at the same time. The sampler plays generated sequencer notes and chord preview notes.
The AUv3 extension is named Cem Olcay: ChordBud 2 and uses the AU MIDI instrument type. It provides one MIDI output named ChordBud 2 Out.
Use the plugin on a MIDI-capable AUv3 track in a host that supports MIDI output from AUv3 plugins. Route ChordBud 2 Out to an instrument track or synth inside the host. The plugin UI uses the same chord grid, timeline, pattern, and sequencer settings as the standalone app.
AUv3 behavior:
The AU parameter tree exposes two automatable parameters:
| Parameter | Range | Default | Purpose |
|---|---|---|---|
| Pattern | 1 to 100 | 1 | Selects the active pattern. |
| Pattern Chaining | 0 or 1 (boolean) | 0 (off) | Enables or disables pattern chaining. |
Automating Pattern selects pattern number equal to the automation value. If the requested pattern does not exist, the selection is ignored. Automating Pattern Chaining only toggles chaining on or off — the chain Mode, Repeat Count, and custom chain steps are saved with the project but are not separately automatable parameters.
The side settings menu is available in the standalone app from the top settings button.
| Section | Setting | Range Or Values |
|---|---|---|
| Tempo | Tempo | 10 to 500 BPM, default 120 |
| Sampler | Sampler | On or off, default on |
| Sampler | Sampler Volume | 0 to 1, default 1 |
| Sampler | Sampler Preset | Presets from the bundled piano soundfont |
| Ableton Link | Ableton Link | Opens Ableton Link settings |
| MIDI In | Virtual MIDI In | On or off, default on |
| MIDI In | Detected input ports | On or off per port |
| MIDI Out | Virtual MIDI Out | On or off, default on |
| MIDI Out | Detected output ports | On or off per port |
| Support | Feedback | Opens email feedback when mail is configured |
| Support | Rate App | Opens the App Store rating flow |
Open this sheet from the bottom-toolbar Settings button in either standalone or AUv3.
| Section | Setting | Range Or Values |
|---|---|---|
| MIDI Settings | Pattern MIDI CC# | 0 to 127, default 10 |
| MIDI Settings | MIDI In Channel | 1 to 16, default 1 |
| MIDI Settings | MIDI Out Channel | 1 to 16, default 1 |
| Chord Input Settings | Input behaviour when a chord is selected | Add to Next, Add to End, Replace |
| Chord Input Settings | When chords overlap | Trim Overlaps default, or Shift Overlaps |
| Chord Input Settings | Chord Progression | Progression types provided by the music theory engine |
| Chord Input Settings | Transpose On Key Change | On or off, default off |
| Scales | Scale checklist | Any scale rows selected from the available scale list |
| Pattern Chaining | Pattern Chaining | On or off, default off |
| Pattern Chaining | Mode | Next, Random, Custom, default Next |
| Pattern Chaining | Repeat Count | 1 to 100, default 1 (Next/Random only) |
| Pattern Chaining | Edit Chain | Opens the custom chain editor (Custom only) |
ChordBud 2 is a MIDI sequencer first. In the standalone app, enable Sampler if you want internal monitoring, or route ChordBud 2 Out to another synth or instrument app. In the AUv3 plugin, route the plugin's MIDI output to an instrument in your host.
Open the side settings menu and confirm Virtual MIDI Out is enabled. If you are using a hardware or network destination, enable that destination under MIDI Out. Also confirm the receiving app is listening to ChordBud 2 Out or the selected CoreMIDI destination.
Confirm Virtual MIDI In or the desired input port is enabled under MIDI In. Then open sequencer Settings and check MIDI In Channel plus Pattern MIDI CC#. ChordBud 2 ignores incoming CC messages unless the CC number and input channel match, and the CC value must be greater than 0.
CC values are one-based. Value 1 selects pattern 1, value 2 selects pattern 2, and so on. If the value points past the number of patterns in the project, ChordBud 2 leaves the current pattern unchanged.
Custom chain steps reference a pattern by its position, not a name. If a step is skipped, check whether the pattern it pointed to was deleted — the step reappears once you re-add a pattern in that slot. If a step plays a pattern you did not expect, remember that adding, deleting, or reordering patterns never edits an existing chain, so a step's pattern number may no longer point at the pattern you meant; open Edit Chain and re-point the step.
Use MIDI Panic! in the side settings menu. It sends note-offs for all 128 note numbers on the current MIDI output channel. Stopping playback also flushes notes that ChordBud 2 is currently holding.
Start the host transport and make sure the host supports MIDI output from AUv3 plugins. Route ChordBud 2 Out to an instrument track. If your host requires record arm, monitor, or MIDI routing setup, enable those options on the destination track.
In standalone mode, set Tempo from the side settings menu or use Ableton Link if syncing with other Link apps. In AUv3 mode, ChordBud 2 follows the host tempo and beat position.
Standalone projects are saved when leaving the project screen or when the app terminates. AUv3 state is saved by the host session. If an AUv3 host does not restore the plugin state, save the host project explicitly and confirm that the host supports AUv3 state restoration or user presets.