Virtual Harmonica

What this virtual harmonica is

This page shows a ten-hole diatonic harmonica in the key of C. Each hole has two buttons, one for the note you get when you blow out and one for the note you get when you draw in. Press and hold a button and the note sounds for as long as you hold it, which is how a real harmonica behaves. Nothing needs installing and no account is required.

The sound is synthesized in your browser from simple waves. It resembles a free-reed instrument, but it is a basic imitation and is not a recording of a harmonica. The board is wider than a phone screen, so on small devices it scrolls sideways.

How a harmonica makes its sound

A harmonica is a free-reed instrument. Inside are small metal reeds, each fixed at one end over a slot. When air passes through the slot, the reed vibrates and produces a note, and its length and weight decide the pitch. The ten holes in the mouthpiece lead to ten channels, and each channel has two reeds: one that sounds when you blow out and one that sounds when you draw in. That is why a ten-hole harmonica can play twenty notes.

In this page, each note is made from a pair of slightly detuned sawtooth waves and a square wave, softened by a filter and given a faint hiss of breath noise. A small note fade-in imitates the way a note builds up when you start to breathe. It reproduces the buzzy character of reeds in a simple way, and does not attempt to match the exact tone of any real instrument.

The note layout in C

The page uses the Richter tuning, the standard layout for a ten-hole diatonic harmonica, in the key of C. Reading holes 1 to 10 from left to right:

• Blow notes: C4, E4, G4, C5, E5, G5, C6, E6, G6, C7.
• Draw notes: D4, G4, B4, D5, F5, A5, B5, D6, F6, A6.

The blow notes spell out a C major chord, so blowing on neighboring holes always sounds consistent. The draw notes, mixed with the blow notes, fill in the rest of the C major scale. Notice that holes 2 and 3 share the note G4 and that the layout lacks a few notes: some scale steps are only reachable by bending, a technique this page does not offer.

Playing with a mouse, touch screen or keyboard

• Mouse. Press and hold a button to sound the note. Hold the button down and drag across the holes to slide from one note to the next, as you would slide your mouth along a harmonica.
• Touch screen. Touch and hold a button, and release to stop. Use several fingers to play neighboring holes together, which is how chords are made on a real harmonica.
• Computer keyboard. The top letter row, Q W E R T Y U I O P, blows holes 1 to 10. The home row, A S D F G H J K L ;, draws holes 1 to 10. Hold a key to sustain the note.
• Keyboard navigation. Press Tab to reach the buttons and hold Enter or Space to play the note in focus.

A single hole can only blow or draw at once, so pressing the draw button releases the blow note in that same hole, just as it would on the instrument.

Blow, draw and chords

Blow means breathing out into the hole, and draw means breathing in. On a real harmonica you control the note with your breath and your mouth, so a beginner's first task is to play a single hole cleanly without touching its neighbors. Here you do that by pressing a single button, and you can also play two or three holes together by pressing several at once.

The easiest chord is blow on holes 1, 2 and 3, which gives C, E and G, a C major chord. Drawing holes 2, 3 and 4 gives G, B and D, a G major chord. Switching between the two is the basis of many simple songs. Many blues players also like second position, called cross harp, where the draw note on hole 2 (G) is treated as home, giving a bluesy sound in the key of G.

Beginner exercises

1. Hear each hole. Play hole 4 blow, then hole 4 draw. Listen to the step up from C5 to D5.
2. The C major scale. Play 4 blow, 4 draw, 5 blow, 5 draw, 6 blow, 6 draw, 7 draw, 7 blow. That is C D E F G A B C.
3. A chord pair. Blow holes 1, 2 and 3 together, then draw holes 2, 3 and 4 together, and repeat.
4. A first melody. Mary Had a Little Lamb is 2 blow, 1 draw, 1 blow, 1 draw, 2 blow, 2 blow, 2 blow, then 1 draw three times, then 2 blow, 3 blow, 3 blow.
5. Ode to Joy. Move up to the middle: 5 blow, 5 blow, 5 draw, 6 blow, 6 blow, 5 draw, 5 blow, 4 draw, 4 blow, 4 blow, 4 draw, 5 blow, 5 blow, 4 draw, 4 draw.

What a virtual harmonica is good for

A virtual harmonica is a simple way to see how the blow and draw layout works before you buy an instrument. It can also help you pick out a tune, learn which holes give which notes, and hear how the two chords above sound. Songwriters can sketch a blues or folk part, and teachers can use it to explain how reeds create pitch. Compare it with the virtual flute, which holds notes in a different, breathier way, and check the pitch of a real harmonica against the online tuner.

Online harmonica versus a real one

A real harmonica is played with the lips, tongue and breath. Players isolate single notes, bend notes down in pitch by shaping the mouth, wobble the sound with the tongue or the hands, and change the volume with breath. A harmonica is also very portable and costs little.

The virtual one lets you hear and see the layout without having to find single holes with your mouth. You press a button for a clear note, but there is no breath to shape. Treat it as a map of the instrument and a place to try tunes, not as a replacement for learning with a real harmonica.

Limitations of this version

• The sound is a basic synthesized imitation of reeds, not a recording, and does not match a particular harmonica.
• Only a ten-hole diatonic harmonica in C is offered. Other keys and chromatic harmonicas are not.
• Bends, overblows and the notes they unlock are not available, so a few scale notes are missing.
• A note's loudness and tone do not change with breath. Volume is set by the slider.
• Nothing is recorded or saved, and there is no MIDI input.

Common problems and how to fix them

• No sound. Browsers keep audio off until you interact with the page, so press and hold a note first. Then check the volume slider, your device volume and the tab's mute icon. On an iPhone, also check the silent switch.
• A note stops when I move. The note sounds only while the button is pressed. Hold it down, or hold the key.
• The keys do nothing. Click an empty part of the page so focus is not in another field.
• Two notes will not sound together. Blow and draw on the same hole are exclusive. Use neighboring holes for chords.
• The sound lags. Close heavy tabs and use wired headphones or the device speaker.