The hand-pumped free-reed keyboard, ubiquitous in Hindustani vocal music since the nineteenth century. For tabla players it is the everyday melodic partner: it accompanies khayal, thumri, bhajan, and ghazal, and it is the standard lehra instrument when a sarangi player is not at hand.
Its fixed tuning and steady sustain make it easy to follow, and lehra played on it keeps the cycle unmistakable — one reason practice rooms favor it. Tabla Focus's Lehra feature is harmonium-voiced for the same reason.