Tuning to shruti: using a tanpura drone in a mix

What shruti means when a singer says C sharp

When a singer says, “My shruti is C sharp,” they mean that C sharp is their Sa, the home note. In everyday studio talk, shruti means the singer’s chosen pitch for Sa. Every other note is measured from that home note, so this tells you where the music is anchored.

Shruti also has a theoretical meaning: the smallest interval of pitch that a trained ear can distinguish. The traditional count is twenty-two shrutis in an octave. That is a different use of the word from a singer naming the pitch they want for a session.

For your production, start with the everyday meaning. Indian music fixes the home note to the voice, not the instrument. If the singer’s Sa is C sharp, set the project around that pitch before recording. Do not choose a key on guitar or keyboard and then ask the singer to fit it.

Find the singer's Sa before choosing the project key

If C sharp feels easy across those phrases, make C sharp the project’s Sa, the home note. If another pitch works better, use that instead. The singer’s usual setting helps you begin, but the song’s lowest and highest phrases decide where you settle.

Choose the project key from that settled Sa before recording any parts. Do not start with a guitar or keyboard key and ask the singer to fit it. The voice sets the home note here. Every other note is measured from that reference, not from an instrument’s preferred starting point.

Once the singer is comfortable, tune the drone exactly to the chosen Sa and keep it there throughout the song. Make sure the singer can hear it clearly in the headphones. That gives them the same pitch reference during the take that they used while choosing the song’s pitch.

Tune a tanpura to the singer's Sa

The tanpura is a long-necked, plucked instrument, usually with four strings. It provides a drone, a continuous pitch reference beneath the melody. Its tuning centres on Sa, the singer's home note, rather than following changes in the melody.

• The usual tuning is Pa Sa Sa Sa.
• Tune the first string to Pa, the fifth, below the home Sa.
• Tune the second and third strings to the middle Sa.
• Tune the last string to Sa an octave below.

A raga is a melodic framework with rules for movement, emphasis and phrasing. When it leaves out Pa, tune the first string to Ma instead. The remaining three strings stay on Sa.

Pluck the strings one after another in a slow, continuous loop. A thread beneath each string at the bridge creates jivari, the buzzing shimmer that fills the sound with overtones, pitches heard above the string's main pitch.

Choose a real tanpura, sample or app

You can record a real tanpura, use a good sample or choose an electronic tanpura app. All three are in common use. The tanpura is a long-necked plucked instrument that supplies a drone, a continuous pitch reference.

• Real tanpura: a recording of the instrument gives the richest sound. Its strings provide the slow rise and fall described above.
• Sampled tanpura: a good sample is also a common choice. It still needs to match the singer's pitch exactly.
• Electronic tanpura app: this can be tuned to any pitch in seconds. It is what most home recordings use.

Whichever source you choose, tune it exactly to the singer's Sa, the home note. If their Sa is C sharp, that is your tuning reference. Keep the chosen drone running for the whole song, without changing its tuning to follow the melody or harmony.

Place the drone behind the voice

In the mix, keep the drone, the continuous pitch reference, lower than the voice and melody instrument. It should sit behind them rather than compete for attention. Let it run throughout the song, including the spaces between vocal phrases.

Keep its stereo width, its spread between the left and right speakers, fairly narrow. Leave the centre for the voice. The aim is a steady reference behind the singer, not a wide layer that draws attention away.

Roll off the lowest rumble below the drone's fundamental, its lowest pitch. Use that pitch as your guide rather than choosing a cutoff without listening. You are removing rumble beneath the drone, not trying to thin out the drone itself.

If you use compression, which controls changes in level, keep it gentle. The drone's slow rise and fall belongs in the sound. Avoid pressing those changes into a constant level just to make the track look more even.

Keep harmony anchored to Sa

Before adding chords, listen to how the melody moves around Sa, the home note. A raga is a set of notes with rules for movement, emphasis and phrasing. Its identity depends on how those notes are approached and shaped, not just which notes appear.

The drone, a continuous sound that provides a fixed pitch reference, keeps Sa in place. Each melody note gets its meaning from its distance to that home note. Chords are not part of the classical sound, so you do not need to add them beneath a vocal.

If the production needs harmony, hold it on Sa and build it from the raga's notes. This is static harmony: it stays put rather than moving through a chord progression. Changing chords changes what the melody notes mean and usually breaks the raga. Using only its notes is not enough if the chords reshape its phrases.

Use pitch correction without flattening the phrasing

Equal temperament is the tuning used by a piano. Pitch correction commonly defaults to this tuning and snaps quickly to the nearest note. That default can work against a vocal shaped by listening to a drone, a continuous pitch reference.

A singer may place a note slightly above or below the piano’s position, or slide into the next note rather than land immediately. Those choices are not automatically mistakes. Aggressive automatic correction can flatten both the pitch placement and the slide.

If you use automatic correction, start gently, with a slow correction speed and the scale restricted to the raga’s notes. A raga includes rules for melodic movement, emphasis and ornamentation, not just a note list. Listen for those details after correction.

For a clearly wrong note, ask the singer for another take if they are available. If they cannot return, correct that spot by hand rather than treating every departure from the piano’s tuning as an error.

Check the recording setup before the first take

Before the first take, check that the session follows the voice. If the singer's Sa, the home note, is C sharp, use that as the project's pitch reference, not the keyboard's preferred key.

• Project pitch: confirm the singer's shruti, their chosen pitch for Sa. Set the whole project to it before recording any parts.
• Running drone: tune the tanpura, the plucked instrument supplying the continuous pitch reference called a drone, exactly to Sa. Keep it running throughout the song without changes.
• Click: use a timing pulse only if the song has a fixed tempo. Do not add one automatically to every session.
• Reference: have a recording of the song at the same shruti ready. Check that its home note matches the pitch chosen for this session.
• Headphones: make sure the singer can hear the drone clearly. Its low level in the mix must not leave the singer without a clear pitch reference.