Watching a concert involving two pianos is rare enough, but when musicians Anil Srinivasan and Sharik Hasan collaborated in a five-city tour last month, they gave Indian audiences an even more unusual experience. Seated before two pianos, the pair performed duets that flowed seamlessly from Carnatic and Hindustani classical to Western classical and jazz.

The concerts were part of a tour titled "Keys to India", which took the duo to Bangalore, Chennai, Delhi, Ahmedabad and Hyderabad to perform six concerts from August 7 to 30. The theme of their tour was harmony, made apparent in the music that wove together influences from the distinct backgrounds of the two pianists, whom are each critically-acclaimed in their own right.

Srinivasan, who comes from a traditional Chennai-based Tamil family, grew up surrounded by Carnatic classical music, but was trained in Western classical piano from the time he was a child. Hasan, on the other hand, grew up in Bangalore with some training in Hindustani and Western classical music. But he found his voice in jazz and is now among the most prominent young Indian jazz pianists.

“Our vision for this tour was that music has no boundaries or barriers, so we thought it would be wonderful to collaborate and bring our different styles and backgrounds together,” said Srinivasan.

Their musical collaboration drew large audiences in public concerts across the five cities – including a midnight concert on Independence Day in Chennai – but there was another aspect of their theme of harmony that attracted some unexpected attention.

“While promoting the concept of harmony, Hasan and I never really spoke about the obvious fact that we come from different communities,” said Srinivasan. “But even that seemed threatening enough to certain fundamentalist outfits.”

Before the tour began, the pianist says he got a phone call from a fundamentalist organisation in Chennai – followed by a letter from another – urging him to shift the focus of the tour away from harmony and merely project it as a musical programme.

“It’s scary that even at a subterranean level, people are threatened by something as harmless as music,” said Srinivasan. “But such reactions merely served to justify what we were planning to do.”

The duo had hoped to begin their tour with a concert in Ayodhya, Uttar Pradesh, but did not eventually get approvals from the city’s authorities, who cited “law and order concerns” as one of the reasons for turning them away.

Nonetheless, Hasan and Srinivasan drew a lot of young audiences in their concerts, which largely followed a spontaneous, improvisational style.

“We did not really rehearse for the concerts, but we had broadly divided the programme into sections addressing themes like nature, romance, the human condition, identity and nationhood,” said Hasan, who sees jazz not as a style or genre but as an improvisational approach.

During the concerts, Hasan and Srinivasan played many of their own compositions, responding to each other’s pianos with music influenced by a style best suited to the moment. While musicians usually play duets with someone on a different instrument, having two pianos playing together poses challenges of its own.

“The piano is an imposing instrument that can easily fill up musical space with both melody and harmony,” said Hasan. “So playing a piano duet is like a game of constant give and take.”