What Tom and Jerry taught me about the music in a kids' game

3 August 2026 · by Larry

A friend posted a Tom and Jerry short this week. I have seen these hundreds of times since I was small, but this time I noticed something I had never really paid attention to: the orchestra never stops.

Not background music. A full orchestra, reacting to every single thing that happens. Jerry tiptoes and the strings tiptoe with him. Tom swings a frying pan and the brass swings it too. Something falls and the whole ensemble falls down a scale after it. The music is not playing under the cartoon, it is playing the cartoon.

Those scores were mostly written by a man called Scott Bradley, and he was doing something quite serious inside a seven-minute cartoon — jazz, snatches of the classical repertoire, sudden changes of tempo, real dissonance when something went wrong. Children absorbed all of that without anybody calling it a music lesson.

I went and listened to the little tune in our own block puzzle after that, and felt slightly embarrassed.

What was actually there

Fifteen seconds. Four chords — the friendliest four chords there are. One tempo. One volume. It repeats, and repeats, and after two minutes it stops being music and becomes wallpaper. My daughter had already told me the first version was "sleepy" and I had made it faster, which fixed the tempo and none of the actual problem.

The problem was that nothing ever changed.

What I rewrote it into

There are now three sections that rotate, and the whole point is that they do not sound like each other.

• A jazz section. Real jazz harmony — the chords are Dm7, G7, Cmaj7 and an altered A7, which is the ii–V–I turnaround underneath a great many songs you already know. The chords land on the off-beats, the way a piano player comps behind a soloist, and the bass walks instead of just thumping the root.
• A lyrical section. Slower, softer, no drums at all. Plain triads, arpeggiated, held long. It is there mostly so the jazz has something to be different from — you cannot hear energy if nothing is ever calm.
• A chase. Faster than either, louder, and built on a diminished chord, which is the sound every cartoon uses when something is about to go wrong. It resolves at the end. That resolution is the whole trick: tension is only pleasant if it gets released.

Two other things, which are small to write and are most of what makes it sound alive:

Swing. In the jazz section the pairs of eighth notes are uneven — the first is long, the second is late. That lilt is the difference between a jazz phrase and a march. I measured it afterwards to be sure it was really there: 0.286 of a second, then 0.168, alternating. That is swing, and it is one line of arithmetic.

Dynamics. The loudness now rises through each eight-bar phrase and eases off at the end, and each section has its own overall level. Nothing in music is at one volume. The old loop was, and that is a large part of why it disappeared into the background.

Being honest about what this is not

It is not an orchestra. I want to be straight about that, because "we added an orchestra" would be a lovely sentence and it would not be true.

There are no recordings on this site. Every sound is generated by the browser as you play, out of simple waveforms — which is why the game still works offline, downloads nothing, and costs nothing to run. You cannot make convincing violins that way. What you can make is the grammar underneath an orchestra: the harmony, the tension and release, the changes of pace, the light and shade. That part is real, and it turns out that is the part that was missing.

Scott Bradley had sixty players. I have some oscillators and a filter.

Why I think it is worth the trouble

Nobody will ever come to our site for the music. It is a block puzzle for kids between maths questions.

But my children hear this thing more than they hear most music, and there is no reason a free game has to sound like a free game. If a five-year-old picks up, without anybody teaching her, that music can be tense and then settle, that it can hurry and then relax, that a jazzy bit and a gentle bit feel different — she has learnt something real, in the same accidental way I learnt it from cartoons.

It is the same instinct as the rest of the site, really. Do the honest version of the thing, even in the corner nobody is looking at.

The music is on the 🎵 button, and off if you would rather it were. And if it drives you mad, that is genuinely useful to know — tell me.

— Larry