Susheela Raman: Woke up this morning at the Eastern crossroads

That Susheela Raman failed to become the first female solo artist to win the Technics Mercury Music Prize this month didn't faze her in the least – and at odds of 28-1 it really shouldn't have. Unlike some of the other nominees, she was thrilled and delighted – and genuinely surprised – just to be shortlisted. And, unlike quite a few more, her career has only just begun. It really takes off next week for the 28-year-old when she appears in two events as part of "The Song's the Thing" festival at London's South Bank. On Wednesday at the Royal Festival Hall she's part of a number of artists (including last year's Mercury winner Badly Drawn Boy) gathered together on the same bill for "A Celebration of Tim Buckley", the influential singer-songwriter who died in 1975 from a drug overdose. Then, on Saturday, she headlines her own concert at the QEH next door.

The music Raman learnt from her Tamil parents was the classical Carnatic tradition of south India. Her Mercury-nominated album, Salt Rain, begins with a song dedicated to the elephant-headed deity Ganesh, written by Dikshitar, a legendary 18th-century composer. Another antique Carnatic song was found in a market in Madras, where Raman's parents have now retired. Lest you think the album is all Open University reading-list stuff, there are lighter moments, such as a version of "Trust Me" from The Jungle Book, and Tim Buckley's "Song of the Siren", as well as Raman's original compositions. Everything, whether ancient or modern, sounds irreducibly her own. And unlike much of what is styled "world music", you don't have to wear terrible trousers to enjoy it. Like the blues, it moans and wails, whatever the language.

"Carnatic music?" Raman says, when I have lunch with her at the family home of her partner (both musical and romantic) Sam Mills in Bradford-on-Avon, Wiltshire. "Being brought up into Tamil culture, my mother felt a strong need for me to learn this music. It's about 2,000 years old and split between north Indian and south Indian forms; the former is influenced by Persian music while the latter isn't. One of the great south Indian composers, also from the 18th century, is Tyagaraja, who would worship the beloved in the form of Rama. He wrote all these incredible love songs addressed to Rama, saying things like, 'Why have you left me here? Can't you see I'm suffering?'"

In other words, it's just like the blues or any lovelorn pop lament. Getting from there to the late Buckley was a natural progression, although Raman was not familiar with his work. "Sam was asked to produce a version of 'Song of the Siren', and as he had to learn it, I did too, and it became a regular part of our kitchen repertoire," she says. "When I eventually heard the Tim Buckley version, I was really struck by it. He sounds drunk, like he's falling on to the microphone, but the conviction is really intense. Sam and I came into the studio one morning, just plugged in, and did it. We weren't going to put it on the record, but when we listened to it the next morning, we thought, mmm, this isn't bad."

As Mills puts Björk's new album on the stereo next door, Raman talks about the singers who inspire her. They include the Afro-Peruvian diva Susana Baca – whom she knows, and whose kitchen in Lima she describes as her favourite place in the world – as well as everyone's favourites, Billie Holiday and Aretha Franklin. She also has a lot of respect for Annie Lennox, after watching her from backstage while supporting the Eurythmics with Joi, the Asian band she fronted in the late Nineties. Then there's the Tuvan throat-singer whom Raman intends to feature on her next record. "He's an octave below baritone and when he sings, the room shakes," she says brightly. We all nod appreciatively, as if this is a very good thing.

'Salt Rain' is on Narada Records. Susheela Raman is in A Celebration of Tim Buckley: RFH, London SE1 (020 7960 4242), on Wednesday, and headlines her own concert at the QEH on Saturday