Diatonic Harmonica Guide: 10 Holes, Keys and Types
A diatonic harmonica is a small mouth organ tuned to one major scale. The standard kind has 10 holes and 20 reeds – a blow note and a draw note in each hole – and covers about 3 octaves. It is made in all 12 keys, and the key of C is the usual first harmonica. Unlike a chromatic harmonica, it has no slide button.
Updated · By the Classfern Music Department
Works in the UK and the US. This version uses US music words (measure, quarter note, staff); the UK version uses bar, crotchet and stave. · UK version of this page
Key facts
- 10 holes, 20 reeds: one blow reed and one draw reed in each hole.
- Range: about 3 octaves (C4 to C7 on a C harmonica).
- 19 different notes: G is on both draw 2 and blow 3.
- Tuning: Richter tuning, created in 1826.
- Made in all 12 keys; the key of C is the standard first harmonica.
- Invented about 1821 (credited to Christian Friedrich Ludwig Buschmann, Germany).
What is a diatonic harmonica?
A diatonic harmonica is a harmonica tuned to the notes of one major scale, such as C major. The usual kind has 10 holes, each with a blow note and a draw note, and is often called a blues harp. You change key by changing harmonica, or by playing in a different “position”.
“Diatonic” means the notes of one scale with no sharps or flats added. A diatonic harmonica in C has no F♯ or B♭, for example, unless you bend a note. That makes it simple to learn, because every hole gives a note that fits songs in C.
What notes are on a 10-hole harmonica in C?
A 10-hole harmonica in C has C, E, G on blow holes 1 to 3 and the full C major scale from hole 4 to hole 7 (C D E F G A B C). The bottom octave has no F or A without bending, and the top holes 8 to 10 give D, E, F, G, A and C.
Hear each hole
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Press a note to hear it and see the hole and breath. The diagram and sound load the first time you press.
| Hole | Blow (breathe out) | Draw (breathe in) |
|---|---|---|
| 1 | ||
| 2 | ||
| 3 | ||
| 4 | ||
| 5 | ||
| 6 | ||
| 7 | ||
| 8 | ||
| 9 | ||
| 10 |
Notice the swap at hole 7: from hole 7 up, the blow note is higher than the draw note. The same layout works on a harmonica in any key; every note is just moved by the same amount. On an A harmonica, for example, blow 4 is A.
What is the difference between a diatonic and a chromatic harmonica?
A diatonic harmonica plays one major scale and has no button. A chromatic harmonica has a slide button on the side: pressing it raises every hole by a half step, so it can play all 12 notes in any key. Chromatics usually have 12 or 16 holes; a diatonic has 10.
| Type | Holes | What it is good for |
|---|---|---|
| 10-hole diatonic (Richter) | 10 (20 reeds) | Blues, folk, rock, country and first lessons |
| Chromatic | 12 (about 3 octaves from middle C) or 16 (about 4 octaves) | Jazz, classical and any key; a slide button adds sharps and flats |
| Tremolo | Varies | Folk music; two reeds per note, tuned slightly apart, give a warbling sound |
| Orchestral (chord, bass) | Varies | Harmonica bands and groups |
Who invented the harmonica, and when?
The harmonica is usually credited to Christian Friedrich Ludwig Buschmann of Germany in 1821, though others built similar instruments at the same time. The Richter tuning still used on 10-hole harmonicas was created in 1826, and Matthias Hohner of Trossingen began mass-producing harmonicas in 1857.
Mass production made the harmonica cheap and small enough for a pocket, and it spread quickly to North America, where it became central to blues, folk and country music. Playing in “second position” (cross harp), the classic blues sound, became common in the 1920s and 1930s.
Is the harmonica hard to learn?
The harmonica is one of the easiest instruments to start: most beginners play a simple tune on a C harmonica within a day or two, because every hole gives a note that fits. Clean single notes take a few weeks of short practice, and bending notes for blues usually takes several months.
- Day 1: blow and draw on holes 4 to 6; play Hot Cross Buns.
- Week 1–4: single notes, the C major scale on holes 4 to 7, easy songs.
- Month 2 and on: second position blues, then bending.
Ten minutes a day works better than one long practice a week.
What is a good beginner harmonica?
A good beginner harmonica is a 10-hole diatonic harmonica in the key of C, with Richter tuning, airtight reeds and a comfortable, smooth mouthpiece. Plastic-comb harmonicas are easy to keep clean. Each player should have their own, for hygiene.
Check that every hole sounds when you blow and draw gently, and that no hole needs a hard breath. Avoid toy harmonicas that are not tuned. Classfern is not connected with or endorsed by any instrument maker.
Quick quiz: harmonica facts
Marked by Classfern 6 multiple-choice questions on the Classfern lesson engine. Your answers stay on this device.
Classfern’s free harmonica tools on lessonplanner.info: the harmonica play-along and hole chart, easy harmonica songs and harmonica song tutorials.
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