Two generations ago, North-South Indian duets were seen by traditionalists everywhere as a breach of purity. Now they have become a popular and often highly creative part of most serious musicians' repertoires, paralleling the boom in fusion. They were given an early boost when Ravi Shankar started getting himself accompanied by a South Indian mridangam and ghatam as well as the expected tabla. This wasn't just to show himself off in a new context; the sitar maestro has always been concerned to give solo space to percussionists, and the quick-fire exchanges that resulted in this expanded situation would drive audiences wild.

They still do. There's one right at the end of the present performance, a fitting conclusion to a long night's music-making. Playing at the 2006 Saptak festival in Ahmedabad, the foursome of sitar player Shahid Parvez, Carnatic flautist Shashank, and a percussionist from each of their traditions Sukhvinder Singh and Patri Satish Kumar were the evening's final act and still going strong well after midnight. It was only the second time that Shashank had played with Shahid Parvez, and it was a pretty spontaneous encounter with no rehearsal, just a discussion of the rag. But a measure of its brilliance is that they have already shared several concerts since, in the US and Europe.