They all make a drone — but not the same one
In Indian classical music, the drone is the ground the melody stands on. Three instruments commonly provide it, and though people sometimes use their names interchangeably, they produce genuinely different sounds and suit different situations.
The tanpura
The tanpura plucks its strings in a slow cycle, and its jawari bridge fills the sound with overtones. The result is a living, shimmering drone that seems to breathe and shift as it rings. For serious raga work — khayal, dhrupad, classical instrumental music — this complexity is exactly what you want: the singer's every note resonates against the tanpura's overtones.
The shruti box
A shruti box is a small bellows-driven reed instrument (the same family as the harmonium), or its electronic equivalent. You open a few stops, pump or switch it on, and it holds those notes as aflat, unwavering drone. There is no plucking cycle and far less overtone movement, so the sound is simpler and more constant — but also louder and utterly steady, which makes it a favourite for group singing, bhajan, kirtan and yoga or meditation settings. It is also easier for a beginner to use than a real tanpura.
The swar mandal
The swar mandal is the odd one out. It is a flat, harp-like zither with many strings, tuned to the specific notes of the raga being performed. Rather than holding the tonic, a vocalist strums it between phrases so its cascade of notes colours the raga. It complements a tanpura rather than replacing it — you will often see a khayal singer with a tanpura droning and a swar mandal resting in their lap.
Which should you use?
- Classical raga riyaz — the tanpura, for its overtone richness.
- Group singing, bhajan, meditation — the shruti box, for its steady volume.
- Adding raga colour as a vocalist — the swar mandal, alongside a tanpura.
In practice you do not have to choose hardware for each. Tirkitprovides a tanpura drone and a raga-tuned swar mandal in one app, both tuned to the same key, and its rock-steady tanpura covers most of what you would reach for a shruti box to do.
