The tanpura’s steady drone is the foundation on which Indian classical music’s ragas are built. But an often unrecognisable part of this instrument is a humble ingredient: a large dried gourd, grown by a small number of farmers and shaped by generations of instrument makers.

Across a few farms in West Bengal and Maharashtra, this film traces the journey of the gourd that gives the tanpura its voice. Farmers inspect fruits by size, touch and sound. Artisans shave and shape them with extraordinary precision. Musicians depend on the resonance they produce. But the lingering resonance of a tanpura note depends not only on the musician, but also on the thickness of a gourd grown months earlier in a field hundreds of kilometres away.

But the tanpura’s tunes are changing.

Farmers, instrument makers and musicians say that the gourds are becoming smaller and more fragile due to environmental conditions. Excessive heat, unseasonal rain, pests and disease are damaging crops. As harvests become more uncertain, so does the future of a craft sustained by specialised knowledge, fragile supply chains and deep emotional ties.

Watch this Mongabay-India news documentary exploring the environmental story hidden within one of Indian classical music’s most essential sounds.