You’re in.

Before you start

• An Apple Silicon Mac: any M1 or newer. This build does not run on Intel Macs.
• macOS 11 (Big Sur) or newer.
• About 1 GB of free disk space.
• Headphones help. A microphone is only needed if you want to record.
• Playing with someone? Keep a voice call open on the side. Mosh syncs the song, not your voices.

Install

1. Download the build with the button at the top of this page.
2. Open the download and drag Mosh into your Applications folder.
3. Open Mosh from Applications.

The build is signed and notarized with Apple, so it opens with a normal double-click. If macOS asks whether to open an app downloaded from the internet, choose Open.

First launch

• The very first launch takes a little longer than usual. Mosh is scanning your Mac for instruments and effects you already own. Give it a few seconds.
• Mosh does not ask for the microphone on launch. macOS only asks when you pick an audio input or arm a track to record. Say yes if you want to record.

Sound check

1. Click + Drum beat above the timeline, then press play. You should hear the built-in kit.
2. No sound? Check the output device in two places: macOS Sound settings and Mosh’s own Settings. They can differ, for example speakers in one and headphones in the other.
3. Crackles or stutters? Raise Buffer in Mosh’s Settings. A bigger buffer trades a little delay for stability.

Play together Optional

1. Both of you click Invite at the top right of the window.
2. The host clicks Create session and sends the room code.
3. The guest types a name, pastes the room code, and clicks Join.
4. You should both see two names in the session. Same song, two windows.

Joining replaces the project open on your Mac with the host’s, and that cannot be undone. Join from a new, empty project.

Things to try

No need to do all of these. Tick them off as you go; the list remembers on this device.

• Drop in a drum beat and loop it
• Add a MIDI track and write a bassline. Double-click a MIDI clip to open the editor
• Add an audio track, arm it, set a count-in, and record something
• Put Mosh AutoTune on that take with + Add plugin
• Ask Moshi for a change, like “more reverb on lead”, then undo it
• Open History and step back through what you did
• Change the colorway in Settings
• Save, quit, and reopen. Is everything still there?
• With a friend: take one track each and build something

Good to know

• You each have your own playhead and your own undo. Pressing play on your Mac does not move your friend’s.
• Agree on tempo out loud. If you both change it at once, the last change wins.
• A short freeze after the host adds an audio clip is normal. The audio file is transferring. It clears in a few seconds.
• A clip that says “source missing” has not finished arriving yet. Ask the host to select that track again so it re-sends.
• Re-Imagine may say it is unavailable. Its audio model is a separate, much larger install and is not part of this download. Skip it this round.

Tell me what happened

The whole point is to find out where Mosh breaks or confuses you. No report is too small, and the good parts are worth hearing too.

• What you were doing, what you expected, and what happened instead.
• A screenshot (⇧ ⌘ 4) or a screen recording (⇧ ⌘ 5) if you can.
• Your Mac model and macOS version, from the Apple menu under About This Mac.
• Anywhere you got stuck, even if nothing technically broke.