It is only about 10 miles from the Royal Albert Hall to Southall, west London, yet they are worlds apart. While one is playing host to the Proms (that most British of -music festivals), the other is a -hectic -community of aromatic -markets, traffic jams, women in saris and men in turbans. Bollywood's -latest hits, bhangra beats and raga rhythms blare from record shops. No wonder it's known as Little -India.
The two cultures will come together on Sunday in what Roger Wright, the -director of the BBC Proms, -described as Bollywood meets Henry Wood, a joking reference to the festival's founder. In fact, it will be a more -diverse, altogether more challenging day of music titled Indian Voices.
In the morning, Pandit Ram -Narayan, a revered figure who plays the sarangi, a lute-like instrument that sounds like a hundred colours (that is, in fact, what a loose translation of the name means), will perform a classical concert.
In the afternoon, the nearby -Kensington Gardens will come alive with sinuous choreography, wildly swirling robes and flashing jewellery as musicians and dancers from Gujarat and Rajasthan honour Lord Krishna, the Hindu deity who -apparently charmed the people with his dancing. There will also be more earthy dances involving fire, swords and snakes - though they probably will not appear on the glades of west London.
In the evening, in what will no doubt attract the biggest crowd, there will be a festival of Bollywood song and dance starring Shaan, who to -Indian audiences is a mix of Johnny Depp, Robbie Williams and, as host of an Indian TV talent show, Simon Cowell.
It is a wide and disparate range of music, much of which is alien to the Albert Hall regulars and, -surprisingly, Little India as well.
The ABC record shop on Southall Broadway stocks only music from the subcontinent, yet on a recent day there was only one recording by Ram Narayan, perhaps the most famous classical Indian musician alive -today.
"Anything by Shaan?" I ask.
"Who?" says the clerk.
"He's that pop star in India," says a woman in a sari waiting to be served.
"Sorry. Don't know her."
If record shops are unfamiliar with the line-up, what can traditional Prommers - mostly white and middle class - make of it all? Will they be able to make the musical leap from Henry Wood to -Bollywood, let alone from the sarangi to Shaan?
Viram Jasani, the chief executive of the London-based Asian Music Circuit, which promotes traditional and contemporary music from Asia, says: "If you look at Indian music, whether it is folk music, classical or Bollywood, there is something in common with all of the styles. There is an Indian-ness that runs through everything. If you understand what that Indian-ness is, you can see why you can have very traditional music in the morning and Bollywood in the evening."
But, Jasani adds mischievously: "First of all we have that problem of defining Indian-ness. After all, we have that problem here in the UK, defining what is British.
"What this day shows you is a kind of journey along a road. The beginning is very early music going back to the Vedas, music that was performed at the fireside for rituals and sacrificial ceremonies. Then there is folk music, which related to the life cycle, to ceremonies of the seasons that were about the work and life cycles of people.
"Then the music moves into a more formal, classical system that is not performed out in the villages, in the open air or in temples but on the stage or in the music room as a very high art chamber music. That's what Indian classical music really is. That, in turn, evolves into a more popular music for the masses, which comes from the films that were treated as a way of escapism from the harsh realities of daily life.
"But what happened with Bollywood is that the quality of the music changed as the Indian diaspora became global. They became less connected with India and Indian traditions and more westernised.
"Bollywood is a reflection of that. It is the dancing that really gets -everybody going. That is the most Bollywood thing about Bollywood. If you look at the dancing today, many people think it is very physical, and yet if you see one of the dancers we are bringing to London, she -dances in the traditional style that the courtesans performed in palaces for the nobility and it is very sexy."
Jasani is a leading sitar player who was brought up in the UK and contributed to a Led Zeppelin record in 1969. "If you listen very carefully to Bollywood," he says, "you will -notice there is a very strong single melodic line just as there is in classical -music, whether it is somebody singing or the orchestra playing.
"There is a rhythm and the singers do not modulate. They stay in the same key. There are the three main elements of classical music: the drone, which gives you one key, the single melodic line and rhythm. That part of it hasn't changed very much, although it is beginning to change with Bollywood because they are beginning to use more western-style harmony."
That combination of the harmonic traditions of the West with India's rhythmic and melodic structure is evident in the work of Devissaro, the founder of Asima, which turns out to not be a female singer as they thought in the record shop but a male vocal group that will open and close the show.
"The same acoustic and -harmonic principles underlie both traditions," says Devissaro, who was born in Australia and trained as a classical pianist before becoming fascinated by Indian music and moving to India in the 1980s to master the pakhawaj (a double-headed drum) and bansuri (bamboo flute).
"The notes of western music correspond directly with the equivalent in Indian music, and the ancient western scales correspond directly to scale forms of Indian music," he says. "Both traditions of music have a common source and evolved into two distinct streams. Western -music has explored the -development of harmony while Indian -music has -focused on the elaboration of melody and rhythm.
"The great achievement of western music over 2,000 years was the evolution of harmony. It has partly to do with its origins as church music and the way the priest would intone a prayer or a chant and the congregation would reply. What happens if you have a congregation of men and women? Naturally, the women are one octave higher than the men. Then maybe some guy couldn't sing in tune but instead of kicking them out of the church, the priest said: 'That sounds pretty cool. Let's keep on doing that.'
"Then you get the next movement, going up and down octaves, and you get a story. So you don't have to keep moving in steps but in opposite -motions.
"It's slow. It took several hundreds of years because with a congregation there were a lot of people involved. But Indian music is a solo art - just one man and maybe a tabla a percussion instrument