Mandar Deshpande, faculty at True School of Music (TSM), and his 19-year-old shishya, Gomathi Iyer, don't know the shape of their upcoming concert with Dharavi Rocks, the trash-can drummers from Mumbai 17, but they know its rhythm. "It will be songs with a heavy percussion," says Iyer.

Originally from Hyderabad, Iyer has trained in Carnatic music under Dr Vyzarsu Balasubrahmanyam for eight years, and joined TSM last year to tackle Bollywood playback, while Deshpande is currently training with khayal vocalist, Arun Kashalkar. The collab with Dharavi Rocks came about because, "It's a great idea to bring different cultures together," says Deshpande. "It's fusion with the music of the masses with the music of classes."