The Beat system is always running in QuickShow, and it can be seen at the top of the toolbar window.
You can set the beat by repeatedly clicking on the “BPM” label next, or by pressing the SPACE BAR on the computer keyboard. You must click the BPM label or press the SPACE BAR repeatedly to the beat of the music. When you do this, the average BPM of the clicks or key presses will be calculated and this will be used to synchronize the timer beat system.
Note that you can press the BACKSPACE key on the computer keyboard to “re-synchronize” the timer beat system to the beat of the music, in case the music timing becomes slightly ahead or behind the timer.
You can also enter a specific BPM, and control other aspects of beats by right-clicking on the Beat icon.
Beats can control certain animations, certain effects, and certain beam sequences
Once the beat is set, it can influence animations (if the cue is setup for Beat-based animation). It can also influence certain effects (if the effect is set to beat-based). And finally, it can also influence the timing of QuickTargets beam sequences (if the particular sequence has chosen to be influenced by beats).