How to host a jam with Combinator

One screen plays the music and every phone in the room becomes an instrument. Here is how to set it up in two minutes, and what to do when something feels off.

What you need

• A laptop or a TV with a browser (Chrome, Edge or Safari).
• Speakers. A cable or HDMI is best; Bluetooth works but adds delay.
• The phones of everyone who wants to play. Any phone with a camera and a browser.
• Optional: a USB MIDI keyboard for the host.

Set it up in five steps

1. Open Combinator on the big screen. On a laptop or TV, go to combinator.club and press Start a jam. Only the host signs in, with a 6-digit code sent to their email. No password.
2. Plug in the best speakers in the room. All the sound comes out of this screen. A cable or HDMI feels tighter than Bluetooth, which adds delay.
3. Everyone scans the QR code. The code is on the screen. Phones open it with the camera: no app and no account. Wi-Fi or mobile data both work.
4. Start the beat. Press Play, or play one of the demos. Each phone picks an instrument: drums, bass, keys, the sampler or the effects pad.
5. Keep what you made. Record the jam into a song, save it to your account, download the song file, or export the audio. A share card sums up the night.

Tips for a good night

• Give each person a different instrument first. Drums and bass make a groove fast; keys and the effects pad come on top.
• Leave everyone in Easy mode at the start. Hits snap to the beat and the keys stay in the song's key, so nothing sounds wrong.
• Stuck for a start? Play a demo and let people play along with it.
• Give the effects pad to the person who says "I can't play anything". Moving a finger across a filter is the most fun job in the room.
• Press "Record to song" when it sounds good, and play the song back at the end.

When something's off

• A phone can't open the link: check that it has internet, then scan again, or open combinator.club on it and type the four-letter code.
• The sound comes late: use wired speakers. Bluetooth adds a delay everyone can feel.
• Crackles on a TV or phone host: choose Smooth in the sound output window.
• Someone stopped the music by accident: on phones, stop needs a short hold, so that rarely happens. Any phone can start the beat again.