So - why is that? Think about that familiar moment when an orchestral conductor comes onto the stage at the start of a performance, silent and motionless for a moment or two.

Then he raises and drops the baton, and you hear a single chord with all the instruments wonderfully in time with each other. This simple visual cue is enough for all the players to come in, synchronised to within a millisecond or two.

It is easy and natural like anticipating the bounce of a bouncing ball.

• When you first play with a metronome, the bounce helps you get started.
• For experienced pros - it makes it much faster to learn new complex rhythms and ones with irregular timing, and helps when working on rock steady timing to "bury the beat".
• For everyone, the bounce continually encourages you to play more exactly in time, much as a conductor does with his baton.

Normal metronomes without bounce visuals can easily encourage you to play off the beat - especially if you are new to metronome practise. That's because it is when you are a fraction out of time that you hear the beat most clearly. Especially with a loud instrument, the click can easily vanish when you hit the beat. And even if that doesn't happen, it is likely to merge at least a bit when you hit the beat, and become less distinct.

So it is only natural to find yourself playing slightly off the beat so you can hear the metronome tick. But it's best to try to see if you can hit the click and make it vanish, or merge, at least for some of your metronome practise time.

That way you can develop really precise time. It's not that you have to be on the beat every time - musicians often play ahead or behind the beat as part of the feel of the music, often intentionally. It is just so you can hit it exactly whenever you want to.

The bounce visuals help with this as they let you see the moment of the click precisely - even when the sound of the metronome tick merges or vanishes. A traditional pendulum mechanical metronome also shows the tick visually - but not with the precision of bouncing ball visuals.

More about that in my page in the bounce metronome wiki How to keep exact time.

This vanishing metronome click is sometimes called "Burying the metronome click" or "Burying the beat". Here are a few links: How to develop rock solid rhythm guitar playing skills (scroll down for burying the click)  - Forum discussion at  ABRSM - Forum discussion at Drummer World. A google search will find much more.

So the bounce helps with that as well.

More thoughts on why the bounce works so well (this blog post is an edited version of that longer page)