Ableton Link™ is a technology, mainly used in music, to synchronize multiple software to a same tempo and to align Beats of every performance. https://www.ableton.com/en/link/  
 

Beat Synchronization and Autoplay

Playback of visuals, generators and Autoplay feature can all be synchronized on the beat of a music. This Beat Synchronization can be performed using different techniques. It requires two components: the Tempo or BPM (Beats per Minutes) and a Start Time so that visuals and music all play aligned on the beat.

The different sources to define the BPM are:

• Audio Beat Detection to deduce BPM from an audio source.

• Manual Beat Detection to deduce the BPM by tapping the tempo.

• Ableton Link™ to detect the BPM from other music software running on the network.
   

To define the precise start for the Beat used to play visuals aligned on the beat:

• In both Audio and Manual Beat Detection the user must press the “Start Beat” button.

• With Ableton Link™ the Beat will automatically start to synchronize on remote sources.
   

When the Beat is started, the Beat Time will automatically be displayed in the application toolbar. The displayed format is:

[Measure].[Beat].[16th]

For instance for the default 4/4 time signature in music, a Measure (or Bar) is subdivided in four Beats, and a Beat is subdivided as four 16th of a Measure.

Setting up Ableton Link™ with these easy steps:

1. Activate “Use Ableton Link” in the Preferences, in the General tab.

2. Start one or more Ableton Link™ software that should drive the rhythm.

3. Toggle on the Link button in the toolbar.

4. Wait till the Link button turns blue and displays the number of applications running Link™.

5. The beat should automatically start and the beat time should be in sync with the other software.

6. You can use the Autoplay, generators or the Beat Synchronization play mode for any visual, to play visual effects synchronized on the Beat of other music software.

7. Changing BPM in one of the application running Link™ will also adjust the BPM in GrandVJ.
 

 Troubleshooting steps:

• Make sure the different software using Link™ run on a same network.
• You might have to wait up to a minute to get the other Link™ software detected.
• Check that the BPM and the Beat Time are synchronized with the remote application.
   

Editing Cell parameters and setting the Beat Synchronization playback mode

In the Visual Tab, a new playback mode has been added to GrandVJ to synchronize a visual on the Beat.  His icon is a wave impulse to symbolize a Beat.
In Beat Synchonization mode the parameter Beats replaces the Speed parameter.

The Beats parmeter illustrated below lets you define how many Beats correspond to the duration of your video loop.