How to sync a bouncing ball to music and MIDI

A ball bouncing in silence is a screensaver. A ball that plays a note every time it hits something is a tiny instrument, and watching it is what makes these loops feel satisfying. This guide covers how notes get attached to bounces in Bounceloop and how to keep the result musical.

How a bounce becomes a note

Each bounce plays the next note of your melody. When the melody runs out, it starts again from the beginning, so a short phrase repeats for as long as the loop runs. Notes that start at the same moment form a chord, and a chord plays together on a single bounce. Harder hits play slightly louder, so a soft touch is quiet rather than silent.

That has a useful consequence: the melody decides the sound, but the physics decides the timing. You do not place notes on a timeline. You write a phrase, and the ball performs it at whatever pace its bounces happen.

Option 1: draw a melody in the piano roll

Open the music panel in the studio. Click to add a note, drag to move or resize it, and press Delete to remove the selected one. The arrow keys nudge a selected note.

A few habits that help:

• Keep it short. Four to eight notes that loop cleanly work better than a long tune, because the viewer hears the pattern repeat and starts to anticipate it.
• Stay in one key. Any note sounds acceptable when every bounce is in the same scale, so random timing never produces a wrong note.
• Use chords sparingly. A chord on one bounce marks a moment. Use it for the finale rather than every hit.

Option 2: import a MIDI file

If you already have a melody, import a .mid file. When the file has several tracks, choose which one drives the loop. Pick a single clear line, such as a lead or an arpeggio, rather than a full arrangement. You can also export the melody you drew as a MIDI file, which is handy if you want to reuse it elsewhere.

Choosing an instrument

Instruments with a quick, clear attack keep individual hits distinct. A music box, pluck, xylophone, marimba or bells are good starting points. A pad blurs hits together, which suits slow, dreamy clips but not busy ones. The Basic and Advanced sound packs add more, including kalimba, steel drum, drums, laser and coin sounds. You can switch instruments while the loop is playing, which makes comparing them quick.

Adding a backing track

To play music underneath the notes, upload an mp3 or wav. Set its offset and volume so it sits behind the bounces rather than competing with them. Only use audio you have the right to publish. Platforms can mute or remove videos that use music you do not have permission to use.

Making the ending land on a beat

Syncing notes to bounces is automatic, but landing the final escape on a particular beat takes a search. Every run is determined by a seed, so the same settings and seed give the same bounces every time. Auto Find tries many seeds and ranks them by how close the finale comes to the time you want. See the seeds and determinism guide for the details.

Busy modes and the note limit

Modes with many balls can produce far more hits than a listener can follow. Bounceloop thins them out so that played notes stay a short, fixed time apart and do not exceed a sensible number per second. The same rule applies in the live preview and in the exported video, so what you hear while editing is what you get.

Next steps

Try the same melody on a different mode and notice how the rhythm changes. A slow mode such as Ring Escape gives a sparse, spacious feel. A dense one such as Merge Cascade gives a flurry. When you are happy with the sound, read how to make a ring escape video or go straight to exporting.