Online Organ

What this online organ is

This page is a playable organ with a four-octave keyboard, from C2 to C6, and nine drawbars that shape the tone. Press and hold a key and the note sounds at full strength until you let go, which is the defining behavior of an organ. Nothing needs installing and no account is required.

The sound is built in your browser from sine waves, so no audio files are downloaded. It is modeled loosely on the drawbar organs made popular in the twentieth century, but it is a simplified imitation, not a recording of a Hammond or a pipe organ.

How organs make their sound

A pipe organ makes sound by pushing air through pipes of different lengths. Each pipe plays one note, and a set of pipes with a common tone is called a rank. The player pulls stops to switch ranks on or off and blends them together. A long pipe sounds low and a short pipe sounds high, which is why large organs hold pipes of many sizes.

The electric tonewheel organ, introduced by Laurens Hammond in the 1930s, takes a different route. Spinning metal wheels generate nearly pure tones, and the player mixes them with sliding controls called drawbars. Each drawbar adds one harmonic, so moving the bars changes the tone from a soft flute to a bright, cutting one. This page follows the drawbar idea, using sine waves in place of tonewheels.

The nine drawbars

The names of the drawbars come from organ pipes. A pipe about eight feet long sounds the pitch of the key you press, so 8' is the fundamental. A 16' pipe sounds an octave lower and a 4' pipe an octave higher. In order, from left to right, the nine drawbars add these pitches compared with the note played:

• 16' one octave below.
• 5 1/3' a fifth above the note.
• 8' the note itself.
• 4' one octave above.
• 2 2/3' an octave and a fifth above.
• 2' two octaves above.
• 1 3/5' two octaves and a major third above.
• 1 1/3' two octaves and a fifth above.
• 1' three octaves above.

Each drawbar runs from 0 to 8. Eight is the loudest and each step down is about 3 decibels quieter, like the numbered positions on a real drawbar.

Presets and building your own tone

The five presets are good starting points. Jazz uses the three lowest bars for a warm, round tone. Full pulls every bar out and sounds bright and large. Gospel adds the highest bar to the warm base for a singing edge. Pipe mixes the octaves in a way that suggests a church organ, and Flute uses a pure fundamental with a soft overtone.

To build your own, begin with the 8' bar alone, which is a plain sine wave, and add one bar at a time. Each added bar brings a new overtone, and you can hear what it contributes. Moving a bar while you hold a note changes the sound at once, and the preset buttons light up when your settings match one of them.

Playing with a mouse, touch screen or keyboard

• Mouse. Press and hold a key. Hold the button and drag across the keys to glide from note to note.
• Touch screen. Touch and hold keys, using several fingers for chords. Swipe the keyboard sideways to reach other octaves.
• Computer keyboard. The bottom row, Z X C V B N M, plays the white keys of one octave, with S D G H J as the black keys. The top row, Q W E R T Y U I O P, plays the octave above. Each key shows its letter.
• Keyboard navigation. Press Tab to reach the keys, use the arrow keys to move, and hold Enter or Space to play the focused key.

The keyboard allows as many notes as your fingers can hold, so full chords work well.

Tremolo

Tremolo is a regular rise and fall in volume. Organists often use it to give long chords movement. This page uses a slow wave, about six pulses a second, to vary the volume, and the slider sets how deep it is. At zero the sound is perfectly steady, which is how a bare organ tone behaves.

This is a simple stand-in for the rotating speaker cabinet that many electric organs use, which also changes pitch and direction as it spins. The page does not model that, so the effect is plainer than the real thing.

Beginner exercises

1. Hear one bar. Pull every bar to 0 except 8', and play a note. This is the plain fundamental.
2. Add overtones. Raise the 4', then the 2', and listen to the tone brighten.
3. Hold a chord. Press Z, C and B together for a C major chord and hold it for several seconds.
4. Change the tone live. While holding the chord, move the drawbars and tremolo and listen to the change.
5. A simple tune. Play C X Z X C C C, then X X X, then C B B, which is Mary Had a Little Lamb.

What a virtual organ is good for

A virtual organ is useful for hearing how a sustained keyboard sound differs from a struck one, for sketching chords and hymn-like parts, and for learning how adding harmonics changes a tone. Because notes do not fade, it is a clear way to practice holding chords and moving smoothly between them. Compare it with the virtual piano, whose notes decay after you press them, and shape sounds further on the online synthesizer.

Online organ versus a real one

A real organ has several keyboards, pedals for the feet, and in the case of pipe organs, a huge range of tones and a sound that fills a building. Organists control the sound with stops, expression pedals and touch. Electric organs add key click, a rotating speaker and overdrive.

The virtual one gives you a single keyboard and a simple additive tone. It is good for ideas and practice, and for hearing what drawbars do, but it does not reproduce the character of a particular instrument.

Limitations of this version

• The sound is built from sine waves and is a simplified imitation, not a recording of any real organ.
• There is one keyboard and no pedals, no percussion and no key click.
• Tremolo is a volume wobble and does not model a rotating speaker.
• The range is C2 to C6.
• 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 a key first. Then check the volume slider, your device volume and the tab's mute icon. On an iPhone, also check that the silent switch is off.
• The sound is too quiet. Check that at least one drawbar is above 0 and raise the volume slider.
• The sound is harsh. Lower the high drawbars on the right, or choose the Jazz or Flute preset.
• The letters play the wrong notes. Check the octave setting. The layout follows the physical position of keys, so on a non-US keyboard the letters on your keys may differ from the labels on screen.
• The sound lags. Close heavy tabs and use wired headphones or the device speaker.