TAMBUM
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TAMBUM

Four children, no shared language — one shared beat.

Five round displays you turn, tap and hold. No text, no menus, no explaining. The first loop is up and running within a minute.

Not for sale yet — but bookable, from €500 per day plus VAT.

01The room

Tuesday afternoon,
Rütli-Campus.

In Berlin-Neukölln, children sit around one table who speak Turkish at home, or Arabic, or Ukrainian. Some are eight, some are twenty. Some were born here, some arrived a few months ago.

This group was not assembled for a study . It is the everyday reality of an after-school centre that has been running two sessions a week for two years.

What do you do with a group in which nobody can be sure the person next to them understands a word they are saying?

3 language groups in a single afternoon — Turkish, Arabic and Ukrainian speaking
8–20 years old. Not a year group — one group
2 years of fieldwork before the first line of code was written
02The problem

Music connects.
Instruments divide.

That making music together brings children together is well documented. A German longitudinal study of 159 primary school children showed it — Turkish, Russian, Ukrainian and Polish speakers playing in one ensemble.

But ensemble playing has a precondition. You have to master an instrument, or learn one. Learning means instruction. Instruction means language.

And the tools meant to work without prior training — apps, software, controllers — almost always consist of menus, icons and English words. Anyone who cannot read, or does not know the language, is shut out again.

This project sits exactly in that gap. There is research on music with refugee children. There is research on tangible interfaces in learning. Where the two intersect, there is so far hardly anyone.

An instrument that needs no explanation is not a convenience here. It is the precondition for taking part at all.

03Get hands on

No text.
No menus.
Turn the ring.

Five round controls on a round table. Four of them are voices; the one in the middle leads.

What you see here is not a picture — it is the instrument, rebuilt in the browser. The drum sounds are the same filesthat also play on the real table. Try it: tap an outer control, turn the ring, then press and hold the middle one.

Sound starts on your first click — browsers only allow audio after a gesture.

Groove grid

Four percussion tracks, four instruments — separate, as in a real kit. The mode you record in decides which row it lands on.

What is real here

04Why round

The shape is
half the teaching.

A round table has no head. No seat is better than any other.

Everyone equally close to the centre

Every child can reach the leading control. Who sets the tempo is not a question of seating — and not a teacher's privilege.

Everyone sees everyone

You can tell whose turn it is from the face next to you, not from an announcement. And you can see the images running on the other discs.

Round has no reading direction

No beginning on the left, no end on the right. On a round display there is nothing you have to turn the right way up first.

The displays really are circles, and text really does get cut off on them — which is why the firmware calculates the chord of the circle for every line.

One line of code that shows what this is about
05What the children changed

The hardest test
is eight-year-olds.

No concept changed this device as much as the afternoons when children actually held it. Three examples.

They got lost — so the menus went

Small children pressed the disc by accident while playing and ended up in a submenu. They could not find their way out on their own. The response was not to explain it better.

Every submenu was removed. Press a control today and you cannot get lost — there is nothing left to get lost in.

“Broken?” — no, just silent

In some states the outer controls deliberately make no sound. That made even the person who built it think twice that the system was broken.

Since then, in exactly those moments, it says “no sound” on the glass. Two words that save half an hour of troubleshooting.

Switching genre used to take 25 seconds. For a child on a stage, that is the difference between an instrument and a computer program.

Today it takes milliseconds.

06What gets learned

Not notation.
Playing together.

Nobody learns to read music here. What children take away are the concepts modern music is built from — through their hands, not through explanation.

Recording a loop means grasping that music runs in rounds. Laying something over it means grasping what a layer is. Turning the ring means hearing that the same rhythm becomes something else with a different sound.

And one more thing, which is rarer: instruments are something you can build yourself. The parts can be ordered, the firmware is readable code, the housing is milled birch.

Play

Tap, listen, repeat. From the first minute.

Understand

Why does this work together? What happens if I change it?

Change

Your own sounds, your own groove, your own order.

Build

For the older ones: solder, flash, read the code.

07The question behind it

What is the best
interface for children
with no shared language?

That is what this is really about. Not a device you can buy — a question that has no good answer yet.

Every decision in this instrument is an attempt to answer it. Why round and not square? Why a ring instead of buttons? Why not a single word on the screen? These are not matters of taste. Each one can be tested on any given afternoon — on children holding it for the first time.

What comes out of it should not be sales figures, but findings other people can reproduce: which shape is understood, which feedback carries, which gesture everyone grasps immediately.

That is why the hardware is documented openly and the code is kept readable. Anyone facing the same group in Hamburg or Vienna should not have to start from zero — and should be able to object when something is wrong.

An instrument that has to be explained has already answered the question wrongly.

What is being tested

Shape, feedback, mapping. Does a child understand without instruction what happens when they turn it?

How it can be measured

Not by whether it impresses — but by whether four children who cannot talk to each other get something made together.

What stays open

Plenty. Whether the shape holds when the group grows. Whether it works with no adult in the room. Whether it is still interesting the third time round.

07 —
Session

Not for sale yet.
But you can play it.

TAMBUM is an experimental setup — there is nothing to order. What there is: five working pucks that I bring with me. A session does not mean watching, it means playing: after ten minutes the first children have built a loop of their own. From €500 per day plus 19 % VAT, including setup, supervision and takedown.

Terms
from €500/ day · plus 19 % VAT
  • Five pucks, speakers and all the equipment
  • Setup, supervision throughout, takedown
  • Travel within Berlin included
  • Half days, multi-day bookings and talks on request
  • No hidden items — travel costs are set out as a formula on the right

For schools and youth centres on a tight budget: ask anyway — different terms apply to field sites where I am allowed to do research.

Schedule
  1. Enquiry via the form below — institution, location, preferred date.
  2. Reply usually within two working days, with a quote.
  3. By arrangement about group size, age, room and power. A table and a socket are enough.
  4. Date — I set up an hour beforehand and stay for the whole time.

Where we observe as well, a short consent form for photos and video is added — voluntary, and the session works without it.

What travel costs

I bill travel by a fixed formula, not by feel. It is always calculated from Berlin-Köpenick, 12555 — from the same point every time, so that every enquiry rests on the same basis. Just type your town in below.

The formula
Berlin, inside the city limitsincluded
up to 50 km from Köpenick€30 flat
over 50 km€0.30 per km
countingboth directions
from 250 km, or starting before 9 a.m.+ €90 overnight stay
several consecutive daysTravel charged once only

Travel time

Driving is working time — the per-kilometre rate only covers the car. Hence a second, tiered item:

up to 50 kmnothing extra
50 – 150 km75 €
150 – 300 km150 €
over 300 km225 €

If the train is cheaper than the car, I take the train and bill the second-class ticket against the receipt — which makes it cheaper for you, not dearer. All plus 19 % VAT. Over several days both are charged only once, which makes long journeys considerably cheaper as a project week than as a single day.

Work it out yourself
Always calculated from Berlin-Köpenick, 12555 — so that every enquiry rests on the same basis.
0 €Travel, net

Examples: Potsdam ≈ 45 km → €30 · Leipzig ≈ 175 km → €255 · Hamburg ≈ 305 km → €498. Road kilometres one way, rounded — the binding figure appears in the quote.

09 —
Enquiry

Request a session.

No contract, no commitment — for now just the question of whether a date works.

Opens the enquiry in your mail program — you see everything before anything is sent.
09Technical

For those who want
the exact numbers.

The rest of this page gets by without these numbers. But if you want to know what happens under the glass — here it is, measured rather than estimated.

What is on the table

Five off-the-shelf rotary displays with round screens, connected to a computer over USB. No custom housing, no custom board design, no battery — those are plans, not built reality. What is built is the software on them.

Controls
5 × M5Stack Dial · ESP32-S3
Display
240 × 240 px, round
Connection
USB takes priority, Wi-Fi is built in
Sound engine
Ableton Live on a MacBook
How fast it responds

Notes go straight from the control to the sound engine. The mediating program only listens in to record — it does not sit in the audio path. Hence the low figure.

Finger → note
1.5 ms
Frame rate
36–43 frames/s
Switch genre
milliseconds (formerly 25 s)
Audio dropouts
none
Sound library

Eight genres, each with its own tempo, sounds and effects. Four percussion tracks and four instruments, each track with 64 slots.

Genres
Hip-hop 90 · House 124 · Techno 132 · Ambient 70
Trap 140 · Funk 110 · Reggae 75 · DnB 174
Tracks
4 percussion + 4 instruments
Sounds per track
64
Sound library
429,086 recordings, indexed and searchable
The moving images

Every sound has its own image. None of them is a video — all are computed, frame by frame. The same images run at the top of this page.

Images
64 in the firmware
Memory
~600 KB of code instead of several megabytes of video
When idle
the image stands still — saving power
On touch
shifting · yielding · thickening
What does not exist (yet)

For the sake of honesty, because on pages like this plans tend to sound like reality:

Housing
designed, not built
Battery
charging circuit present from the factory, not populated
Loop game
flow is set, game logic to follow
Custom board
planned for later
11 — Newsletter

The TAMBUM newsletter.

About once a month, and only when there is genuinely something to report: new session dates, progress on the instrument, findings from the classroom — and word when TAMBUM is actually for sale.

Your address is never resold, no third-party advertising, one-click unsubscribe in every email.

No newsletter service yet: the sign-up opens as a ready-made email, nothing goes out unasked. Before the public launch, a proper provider with double opt-in and an unsubscribe link will be added.