Oh no! Sawhney's off talking about physics again...

Nitin Sawhney has lost me. Despite my best mental efforts, I just can't keep pace with his verbal sprint through several millennia of philosophies this early in the day. The musician has skipped from the Hindu Vedas to Einstein via Kepler and Heisenberg, and all before his first sip of coffee. So I'm surprised when he claims not to understand why people call him "intense".

Sensing my bemusement, he plays his trump, or rather, rump, card. It is Sawhney's backside that features at the end of the "Going for an English" restaurant skit that turned Goodness Gracious Me into a hit comedy. "That was mad. That was me burping at the beginning and doing a moony at the end," he laughs. "When people say I take myself seriously, I say, 'Just watch me do a moony'."

Sawhney, of course, did a lot more than just play a cheeky cameo in the satirical send-up of the British love affair with curry. The musician, who has just become an associate artist of Sadler's Wells, was once better known as one half of The Secret Asians, the radio double act with Sanjeev Bhaskar that became Goodness Gracious Me. Sawhney bowed out after making the television pilot. "I was producing someone for Warner Brothers at the time and said, I can't do this and that. I'm a musician. I didn't realise it was going to get so bloody popular!"

Not that he's bitter. For one thing, he hasn't got time. As well as co-starring in Confluence, a dance collaboration with the acclaimed choreographer Akram Khan that opens this week at Sadler's Wells, he is working on a new album, his ninth, for next May, plus the soundtracks for Midnight's Children, the first of Salman Rushdie's novels to be adapted for the big screen, and the BBC's autumn nature series, Human Planet. Then there's his plan to dramatise a conversation Einstein had with the Bengali philosopher Rabindranath Tagore in Caputh, Germany, in 1930 that to my untutored mind smacks of Michael Frayn's Copenhagen.

"Einstein and Tagore swapped notes about how physics and Hindu philosophy and music were all related to each other," Sawhney explains in his new Brixton studio. "It touches on everything I'm interested in."

He is clearly very busy with Midnight's Children, although such is the secrecy that has been drawn over the project that he cannot divulge any details. "It's going to be amazing. Deepa Mehta is my favourite director; she's brilliant," is all he will say.

I'm keen to dwell on the concepts I can actually comprehend, such as his score for Human Planet, which is the BBC's first big post-Attenborough delve into the natural world; anything to stop Sawhney spouting more theoretical physics. However, it's hopeless to think I can steer him away from the topic for long. Sawhney is soon back to his favourite topic. In his mind, physics and music are almost one and the same, such is the overlap between the disciplines.

I can't help thinking that Sawhney is wasted as a musician. Stick him in a classroom, and the T-shirt-and-jeans-wearing 46-year-old would probably inspire a whole generation of teenagers to become scientists.

It was his interest in theoretical physics, combined with ancient Indian philosophy, that inspired Confluence. "We started talking about where creativity came from and we thought about people like Michelangelo, who said that the statues were already hidden in the marble around you. Or Ravi Shankar, who said the raag exists in the air around you. Or John Coltrane, who talked about improvisation being like a bird that you have to catch in the air,"he says.

Although Sawhney's father was a scientist – he worked as a chemical engineer – it was his mother, a dancer, who got him into Hindu philosophy. "My mum once told me there were lots of coincidences with theoretical physics and ancient philosophy. Now I'm into all the maths, too. I'm fascinated by the Large Hadron Collider at Cern and the whole idea of trying to find the God particle."

I'm on safer ground with Sawhney's music and tell him I'm impressed he has collaborated with many major artists such as Sir Paul McCartney and Madonna. But he shakes off the praise. "I'm a musical explorer. I just try to have adventures through music." If this takes him on a world tour of styles and genres, then so be it. He doesn't set out to create "world music". Indeed, he deplores the term.

"It fascinates me that people sometimes listen with their eyes," he says, referring to his project with the Royal Opera House called Entanglement, which divided the critics. "People will look and assume one thing, as opposed to really listening. What I find frustrating is that as soon as someone sees a name like Nitin Sawhney, they will make an assumption."

This explains why he was no fan of the BBC's Asian Network, which he viewed as musical "apartheid". He says: "It's racism. The number of albums that make it in the top 100 that are by Asian artists is totally disproportionate to the demographics of this country. Something needs to change." He is not optimistic. "We seem to be going backwards. It's like this travesty of an election, where basically the whole thing was focused on immigration. Since 9/11 and 7/7 it's been a real opportunity for racists to come out of the woodwork."

Language like that I can understand. But something tells me it is going to take a lot more than some funny Asian satire before Britain fully accepts its multicultural heritage.

'Confluence' is at Sadler's Wells from Tuesday until Saturday www.sadlerswells.com

Never too old Veteran rock stars put young 'uns in the shade

Who says there's no money to be made in the music business any more? While downloading may be killing the rock stars who rely on album sales, there is still a welter of cash around for those on tour.

A glance at the Forbes list of the top 10 grossing bands of last year shows only a slender presence by the shining lights of Generation YouTube. Instead, the list is mostly full of more venerable rockers who have completed massive tours.

The list is topped by U2 with gross earnings of £84.9m thanks to their global 360 tour. Second are the veteran Aussie hard rockers AC/DC, with £74.5m from touring and the Iron Man 2 soundtrack. Beyoncé is third with £56.8m; Bruce Springsteen fourth with £45.7m, and fifth is Britney Spears with £41.8m.

Not until we get to number seven, and Lady Gaga, do we find a breakthrough artist. Lady Gaga is queen of the downloads – Poker Face was downloaded four million times. But the revenue from that will have been dwarfed by ticket sales from the New Yorker's outrageous shows.

The music broadcaster Paul Gambaccini points out that the Black Eyed Peas, joint 10th with Coldplay, are the other representatives of the download generation, holding the record with five million downloads for "I've Got A Feeling".

"It's no secret that album sales have gone through the floor," he said. "If we go back to the 1960s and Seventies, artists put out a couple of albums a year, thereby building up two-and-a-half hours of hits which is what people want to see. A band such as Oasis, by contrast, only got as far as Sgt Pepper, if you like, but over a much longer period. This has led to a crisis in concert promotion in the US. So it's no surprise that the biggest earners are veteran bands with a catalogue of hits. Also, downloads are cheaper than CDs, so you don't make as much money from them."

But even the lucrative concert business may be wilting. Live Nation, which recently merged with Ticketmaster to become the most dominant force in live music, recently announced that ticket sales for its top 100 acts dropped 9 per cent this year, amid a 17 per cent drop in the concert business at large, and it expects further falls.

"Everybody was surprised by how well the business held up last year, despite the economy crashing around us," said Gary Bongiovanni, the editor of Pollstar, a trade publication.

Andrew Johnson