Music theory step by step: reading notes, rhythm and intervals – building on one another, with short units and clear progression. For school, music lessons and home.
Reading notesRhythmIntervalsSolfègeBoomwhacker coloursGlossary in 4 languagesOffline
What you learn
The fundamentals, cleanly built up
Klang-Spektrum guides you through the most important topics of music theory – clearly, in small steps and with repetition, so that it really sticks.
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Reading notes
From the staff through treble and bass clefs to the note names – the written language of music from the ground up, with mnemonics for quick recognition.
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Rhythm
Note values, rests, time signatures and tempo: listen, count out loud and tap along until the pulse sits securely.
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Intervals
Recognise and name the distances between notes – with listening examples and familiar anchor songs.
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Solfège & colours
Do-Re-Mi and fixed sound colours make pitches tangible and easier to remember – especially for inner hearing.
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Glossary
Look up the most important technical terms briefly and clearly – available in four languages.
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Listening & applying
Ear-training exercises connect theory with real sound – because knowledge truly comes alive only through listening.
The learning idea
How you learn with Klang-Spektrum
Music theory rarely fails because of ability, but often because too much comes at once. Klang-Spektrum therefore relies on a few proven principles from learning research – the same ones that work in good music teaching:
Small units: Each topic is broken down into manageable steps. Practising just one concept at a time means you retain it more reliably.
Building on each other: First the note names, then rhythm, then the distances – each new topic rests on the previous one. That way no gaps appear.
Repetition with spacing: What you have learned keeps coming back, rather than being ticked off once. This distributed practice (spaced repetition) anchors knowledge for the long term.
Hear, see, do: A note is seen, heard and reproduced. Addressing several senses at once consolidates learning markedly better than reading alone.
Short, regular sessions – around ten minutes a day – achieve more than rare long ones. That is exactly what the app is designed for: a little further every day rather than a lot at once.
Two tools explained
Solfège and sound colours – why they help
Solfège: Do, Re, Mi
Solmization (solfège) gives each degree of a scale a syllable: Do, Re, Mi, Fa, Sol, La, Ti. In the common “movable do” form, Do is always the tonic – whatever key you sing in. This way you learn the relationships between notes, not just individual names. “Ti”, for instance, audibly leans back up to “Do”. Anyone who can sing melodies in these syllables develops “inner hearing” and pitches notes more securely.
Fixed sound colours (the Boomwhacker principle)
In the colour-coded approach every note is given a fixed colour – the same principle as the well-known Boomwhacker chime tubes, where C is red, for example, and the notes follow a rainbow-like order. For beginners this is a bridge: before abstract notation is firmly in place, melodies can be recognised, played along with and memorised through colour. Colour speaks to the eye, sound to the ear – together they make pitch graspable.
For school & home
Made for the classroom
Age-appropriate from 10 years
Klang-Spektrum is designed for 10- to 17-year-olds and can be used without prior knowledge – in music lessons, in a club or for practice at home. Parents and teachers will find how to use the app in everyday situations in the School & Family section.
As a starter: Go through a short topic together at the beginning of the lesson and then apply it on the instrument.
For differentiation: Faster learners practise on independently while others repeat a topic at their own pace.
As homework: Spend ten minutes a day deepening one topic – that fits well between lessons.
For reference: Clarify unclear terms directly in the multilingual glossary, also for learners with another first language.
Common questions
FAQ
What age is the app intended for?
Klang-Spektrum is aimed at young people aged roughly 10 to 17. For younger children (from 6), the sister app Klang-Regenbogen is the better, playful introduction.
Do you need prior knowledge or an instrument?
No. The topics start from scratch and build on each other. An instrument is not necessary, but helps you apply what you have learned right away.
Which topics does the app cover?
The focus is on reading notes, rhythm and intervals, complemented by solfège, colour-coded pitches, ear-training exercises and a multilingual glossary.
Can I also read up on the topics without the app?
Yes. All topics are available as free learning pages in the browser – ideal for preparing and reviewing, or for revising without a device.
Why a flute sounds different from a violin — on exactly the same note
When a flute plays the A above middle C and a violin plays the same note, both vibrate 440 times per second. The pitch is identical, measurably identical. Yet anyone can tell within a quarter of a second which instrument is playing. The difference is not in the pitch but in what sounds above it.
A vibrating string or column of air never vibrates only as a whole. It vibrates simultaneously in halves, thirds, quarters and so on. Each of these partial vibrations produces its own tone: the half at twice the frequency, the third at three times. These are called partials or overtones, and their frequencies are always whole-number multiples of the fundamental. For a fundamental of 110 Hz they fall at 220, 330, 440, 550, 660 Hz and upward.
What this series produces musically is remarkable. The second partial lies an octave above the fundamental, the third a fifth above that, the fourth another octave, the fifth a major third. The major triad is therefore physically present inside every single note an instrument produces. That is not a quirk of Western music but a property of vibrating bodies — and the reason major is heard as stable and settled across cultural boundaries.
Reading a spectrum
A spectrum shows exactly these partials as bars: frequency along the bottom, strength up the side. The leftmost bar is the fundamental, the ones that follow are its overtones. The pitch lives in the spacing of the bars, the timbre in their heights.
The flute has a strikingly sparse spectrum. The fundamental dominates, the second partial sits at roughly a fifth of its strength, and everything above that nearly disappears. Physically a flute is close to a pure sine wave, which is why it sounds soft, round and slightly hollow. The violin, by contrast, has a dense spectrum: the fifth partial is still half as strong as the fundamental and the eighth is clearly audible. Those high partials give it the brilliance and edge with which it cuts through an orchestra.
From this follows a rule you can actually apply when scoring: overtone-poor sounds blend well and recede, overtone-rich ones assert themselves and sit badly together. Two flutes in unison sound like one instrument; two oboes remain two oboes.
Formants — why you can tell an “ah” from an “ee”
The singing voice adds a second mechanism. The vocal folds produce an overtone-rich raw sound; throat, mouth and nose form a resonating space above it that boosts certain frequency bands and damps others. The boosted bands are called formants, and their position decides which vowel we hear.
The numbers involved are surprisingly stable. For “ah” the first formant sits at roughly 700 Hz and the second at 1200 Hz; for “ee” the first is low at around 300 Hz while the second is high at about 2500 Hz. For “oo” both are low. The crucial part: these values stay roughly the same whatever pitch is being sung. That is why the vowel is recognisable independently of the note — the fundamental moves, the formants stay put.
This is also where singing meets a limit that sopranos know in practice: once the fundamental rises above a vowel’s first formant, that vowel can no longer be formed cleanly. High in the range singers therefore modify their vowels, and an “ee” is carried closer to an “ih” or “ah”. That is acoustics, not carelessness.
The so-called singer’s formant is a related phenomenon: trained operatic voices concentrate extra energy at around 2800 to 3200 Hz. An orchestra is comparatively quiet in exactly that band and the human ear is particularly sensitive there. An unamplified voice carries over a full orchestra not because it is louder, but because it sits in a gap.
What to do with this in a lesson
The most convincing demonstration needs no equipment. Silently depress the notes C–G–C–E in the upper half of a piano, hold the keys down, then strike the low C firmly and release it. The silently held strings keep sounding — they have been set in motion by the overtones of the struck note. Children hear for the first time that a single note contains notes.
On the guitar the same thing works through harmonics. A finger that merely touches the string over the twelfth fret instead of pressing it forces a node at the midpoint and sounds the second partial, an octave higher. Over the seventh fret comes the third partial, a fifth above that; over the fifth fret, the fourth. The fret positions are therefore directly readable division ratios of the string: 1/2, 1/3, 1/4.
A third route is overtone singing, which succeeds with teenagers surprisingly often. Sing a low, steady “oo” and slowly change the shape of the mouth towards “ew”, “oh”, “ah”, “eh”, “ee”. Done patiently, a high flute-like tone detaches itself from the sound — a single overtone, brought out by the changed mouth position. That is the formant, made audible.
Read freely
The theory is also available in the browser
All topics of the app are available as free learning pages – ideal for preparing or reviewing.