User Guide

Available as a standalone app and an AUv3 plugin for iOS, iPadOS, and macOS, Bar Sequencer brings together the ease of a metronome with the dynamic capabilities of a sequencer.

The app focuses on displaying a single bar (measure) at a time, while allowing you to add an unlimited number of bars to your sequence. Each bar can have a distinct meter (time signature) and beat division.
Individual segments correspond to specific music notes or sounds, whose attributes can be adjusted accordingly.

Tracks can also be added without constraints. Each track corresponds to a MIDI channel, driving various patches or instruments.

The tempo remains consistent throughout the entire project. You can choose to sync with your host application or maintain an independent tempo.

The standalone version features a built-in library of essential sounds. In contrast, the AUv3 plugin serves as a MIDI processor, interacting seamlessly with a wide range of third-party instruments.


  1. New
    • Create a new default project/preset.
    • A confirmation dialog appears to prevent accidental loss of the project.
  2. Open
    • Load a user project/preset.
    • There is no confirmation dialog when overloading an unsaved project, as this is already a two-step operation.
  3. Save
    • Store a project internally and as a user preset in the AUv3 environment.
    • There is no confirmation dialog when overwriting an existing preset with the same name, as this is already a two-step operation.
    • In the AUv3 environment, loading and saving presets for the Plugin is also available from within the Host app.
      Sometimes the Host’s mechanisms can provide additional possibilities, such as ‘export to file’ (e.g. Logic Pro).
    • The preset does not include information about the loaded sound library. It contains only sequence-related information such as tracks, bars, tempo, etc.
    • The current project ‘working copy’ is auto-saved periodically, so it’s loaded automatically on start.
  4. Help
    • Open this user guide.
  5. Shopping cart
    • Purchase an Essential Sound Library for the standalone application or remove the time limit in the AUv3 plugin.
    • Purchasing the AUv3 plugin is available only from within the standalone app due to limitations of the Apple App Store mechanism.
  6. Settings
    • Available only in the standalone app.
    • The Settings are described later in this guide.

Main View

Main View
  1. Preset name
    • Optional information about the current project/preset (empty for a new, unsaved project).
    • An asterisk symbol indicates if the project has been edited or modified.
      Save the preset to update it.
  2. Bar number
    • The currently played or displayed bar.
  3. Track number
    • The currently displayed track.
    • If a track name is set, it will be shown next to the number.
  4. A Bar Circle / Segments
    • One bar circle is divided into segments.
      Every segment corresponds to one music note.
      The position of the segments corresponds to the note’s position in the bar.
    • The currently playing segment is highlighted.
    • One tap/click on the segment activates or deactivates the note, indicating whether it will be played or not.
    • Long press on a segment to open a note’s properties sheet.
    • Swipe horizontally to view any bar on this track for editing purposes (disabled while playing).
  5. Playhead position indicator
    • Indicates the position of a beat on the currently played bar.
  6. Add bar
    • Add or insert a new bar next to the bar on which the button was tapped.
    • The new bar is a copy of the previous one.
    • This button is disabled while playing.
  7. Remove bar
    • Delete this bar.
    • This button is disabled while playing.
    • There is no confirmation dialog.
  8. Edit bar
    • Open the properties sheet for the bar.
  9. Add track
    • Add a new track with one bar. The new bar is a copy of the first bar of the previous track.
    • New tracks are added always at the end (not inserted after the current track).
    • This button is disabled while playing.
  10. Remove track
    • Delete this track.
    • This button is disabled while playing.
    • There is no confirmation dialog.
  11. Mute track
    • Notes on this track won’t be played and visually highlighted, but the position indicator works as usual. You can mute/unmute it any time while playing.
  12. Edit track
    • Open the properties sheet for the track.
  13. Up / Down arrows
    • Scroll vertically between tracks for playback or editing purposes.
    • This button is disabled if there’s no next or previous track to scroll to.


  1. Host / DAW sync
  2. (available only in the AUv3 plugin)
    • Toggle synchronization with a host on and off.
    • When synchronization is active, transport buttons and tempo controls are disabled.
    • Only the tempo and the playhead position are synchronized.
    • The time signature is not synchronized by design, as it is not related to the whole project and can be different for each bar.
  3. Tempo controls
    • Tempo is global for the entire project.
    • There are three methods to change the tempo – using the stepper, tap tempo button, or slider.
  4. Transport section
    • Buttons for controlling the transport state – playing, stopped or paused.

Segment sheet

Segment sheet
  1. Active toggle
    • Make the note active or inactive. Indicates whether it will be played or not.
  2. Velocity
    • A MIDI value in the range of 0-127.
    • It affects not only the volume, but also the sound itself, as different samples can be played based on this parameter.
    • The color saturation of a corresponding segment is adjusted accordingly.
  3. Duration
    • The time the MIDI Note Off event is sent after the corresponding Note On event and no later than the next Note On event.
    • Typically affects melodic sounds with sustain, not percussion.
    • The visual length of a corresponding segment is adjusted accordingly.
    • Double tap/click on the label or value to reset this to default maximum length.
    • It’s possible to set this value to infinity, meaning that the MIDI Note OFF signal won’t be sent for this segment.
  4. Left / Right arrows
    • Navigate to the previous / next segment.
    • When the segment sheet is open, you can tap on a segment on the main circle to select it for editing.
  5. Piano keyboard
    • Scroll horizontally to view all the keys.
    • Tap/click on a key
      • Assign a note to this segment.
      • You will hear the corresponding sound immediately if the transport is stopped or paused.
        While playing, you’ll hear it when it’s its turn.

Bar sheet

Bar sheet
  1. Time signature (meter)
    • A time signature is assigned to each bar independently.
      There’s no global time signature for the entire project.
    • The upper numeral is a value in the range of 2-16.
      • Indicates how many beats constitute a bar.
    • The lower numeral is one of the following values: 1, 2, 4, 8, 16.
      • Indicates the beat value. The higher the value, the shorter the beat.
    • The number of notes (segments) in one bar equals the number of beats multiplied by the Beat division.
  2. Bar repeat
    • If there’s more than one bar in the track, this number indicates how many times this bar is played before the next bar is played.
  3. Beat division
    • The number of notes (segments) per beat.

Track sheet

Track sheet
  1. Track name
    • You can enter something meaningful here, e.g. the Patch name.
      It will be shown next to the track number on the main view.
  2. MIDI channel
    • A value in the range of 1-16.
    • In the standalone app settings, there’s a mapping section where you can assign a patch (sound) to a MIDI channel.
    • In the AUv3 environment, this number applies to other instrument plugins driven by this plugin.
    • You can assign the same MIDI channel number to multiple tracks.


(not available in the AUv3 plugin)
  1. Sounds
    • Sound Library picker
      • Visible only if the Essential Sound Library hasn’t been purchased yet.
      • Check the Essential Sound Library’s capabilities in the demo mode.
    • MIDI Channel—Patch mapping
      • Assign a Patch (i.e. Instrument or Sound) to a MIDI Channel.
      • You can assign the same Patch to multiple MIDI channels.
      • Tracks that are linked to a given channel number will play the sounds of the corresponding Patch.
  2. MIDI
    • Outputs
    • The standalone app can send MIDI events to:
      • The Bar Sequencer virtual port (which is visible as an Input for other apps)
      • Other apps’ output virtual ports
      • Internal MIDI bus (IAC Driver, available only on macOS)
      • Other MIDI devices connected via USB, Bluetooth or Network (mostly Wi-Fi)
      Although it’s possible to select more than one MIDI output, in most cases it’s recommended to choose only one of them, to avoid unintentional multiplying of MIDI events.
    • BT (Bluetooth)
      • Section allowing pairing other MIDI devices.
      • The Bar Sequencer can act as a Bluetooth host or peripheral.
      • If a paired BT device is connected, it appears as an Output in the section above.

Demo timeout

There’s a 3-minute time limit in the demo version.
The timer restarts each time you reload the plugin, or select the non-demo sound library in the standalone app settings, so you can test it as many times as you want.
After the time has elapsed, the plugin stops sending MIDI events to the Host or the limited sound library is loaded in the standalone version.

System requirements