Choosing Sa and the drone

The line beneath the title names your scale. The Sa buttons and Scale (Sa) dial lower or raise the tonic by semitones from G2 to B3, stopping at both ends. Sa defaults to C sharp in the vocal register. The drone holds Sa and Pa, with its own switch and volume knob, and waits for your first keypress.

The stops

The stops are above the keys on wide screens, and below the instrument on every screen. Bass is an octave below Male, the default voice, and Female an octave above. Each has a left-hand switch, but the last enabled stop stays on. The coupler adds an upper octave at its own level.

Level sets loudness from 0 to 100 percent. Tone sets a low-pass from 400 Hz to 12 kHz, or fully open. Beat detunes a second reed by 0 to 12 cents, with 0 leaving one reed. Reset restores the default sound. The sound is a recording of one real harmonium reed note, looped by ear.

Playing from keys or touch

On laptops, Home row puts Sa on D, Re Ma Pa Dha on F H J K, and upper Sa on the semicolon. Ga and Ni use B and the full stop, with komal and tivra notes on C V N M and the comma. Q W E R T Y and digits cover the lower octave, while I O P and brackets cover the upper.

Keyboard layout lets you name up to eight layouts and drag notes onto computer keys. On phones and tablets, Position selects the touch keyboard's visible keys, and Key width sets 30 to 60 px per key. Drag anywhere on a control, not just a thumb. Enable MIDI in Settings to use a MIDI keyboard.

Choosing scales and tracking pitch

Under the keys, Sustain lets released notes ring for 0 to 5 seconds. Volume sets loudness, Reverb adds reverberation, and Labels selects Latin, Devanagari or Bengali names. The scale stepper or sheet offers ten Hindustani thaats and seventy-two Carnatic melakarta scales for lessons. Highlight raga notes lights that scale and dims the rest.

Pitch track toggles microphone and graph, requesting access once. It learns how loud the reed is, then draws only your voice against the swara grid. After reloading, the graph reopens if microphone access is already allowed. Otherwise, “The microphone is off” appears until you tap. Refused access leaves the graph open with a message.

Practising with written notes

Practice starts beside the instrument, below on phones, with the scale, four alankars and recent lessons. Its 223 lessons include Bhatkhande's twenty alankars from Kramik Pustak Malika's first book, everyday paltas and twenty-four merukhand orders. Carnatic exercises cover sarali, janta and alankaram. Seventy-four ragas include ascent, descent and difficulty out of ten.

Pace sets lesson playback in matras per minute. Expand enlarges lessons written in phrases or taal tables, with one matra per cell, vibhag bars and clap signs. Type your own alankar in one cell and the app writes its three-octave climb the way the book does. The live sargam readout names played notes.

Recording a take

Record saves two tracks, the instrument as heard and your voice, with an account and 200 MB free. Without one, sign-in opens. Recent takes appear below and on Recordings, where you can rename or trash them. Recording continues across site pages.

Display and settings

Display switches cover Auto-bellows, sargam labels, Western names beneath sargam and Keyboard hints on laptop and touch. Auto-bellows follows the sound as bellows fill and leak. Settings selects microphone and output devices. Preferences follow your account across devices, or stay in the browser.

The Learn section has alankars and harmonium notes for ragas, with one page per thaat. It has no film song notations. Ear training plays a note or passage for you to sing back on Pitch track, then answer on the keys.

Where the harmonium came from

Alexandre Debain patented a foot-bellows reed organ in Paris in the 1840s. A Mumbai player notes that Debain also made smaller hand-pumped versions. Hand-pumped harmoniums for floor-seated playing were made in Calcutta by 1875. A widely held account credits Dwarkanath Ghose's workshop with cheaper, more durable instruments, though that account may be incomplete.

Many Indian harmoniums have mechanical scale changers, shifting keyboards against reeds while preserving fingering, as the Sa dial does in software. All India Radio banned the instrument from broadcasts as un-Indian in 1940. The ban was partly lifted for accompaniment in 1971, but solos remained excluded. In 2011, ethnomusicologist Matthew Rahaim argued that it served an attempt to define a national sound distinct from the West.

It accompanies bhajan, kirtan, qawwali, ghazal and a singer's riyaz. Sing Sa against the drone and a held key, then release it and check your voice on Pitch track.