"Southern Counties Radio asked us to bring in some sackbutts and a lute at 7.30 in the morning!" laughs Clare Norburn.

"Firstly, these are professional musicians we're talking about so you can't get them out of bed before ten. Secondly, we haven't got any sackbutts."

A singer with Mediva, the upbeat group known country-wide for their success in bringing Medieval music into the 21st Century, Norburn is also co-director of the Brighton Early Music Festival, which returns today following its inception last autumn.

One of the most exciting and ground-breaking events on the musical calender, the festival is already the second largest of its kind.

And, though they're all out of sackbutts this time, what they do have is a dynamic, 17-concert programme with leading international names performing some of the most spine-tingling music known to man.

"Early music really isn't of marginal interest," says Norburn. "It sometimes gets called the 'authentic music movement' but that sounds a bit stuffy and boring - I think we should be the 'very old and very interesting movement'.

"You can tell if something's early music because it uses modes we're not used to hearing. The earlier string instruments, especially, are mellower, purer and much more beautiful."

The opening concert, On Wings Of Song (All Saints Church, Thursday September 30, 8pm) is also historically the most recent. Featuring Mendelssohn's compositions alongside the lesser-known songs of his sister, Fanny, it stars soprano Catherine Bott, presenter of BBC3's Early Music Show, accompanied on the fortepiano.

At the same venue the following evening, you can see Emma Kirkby, "the voice of early music", celebrating the work of England's best-known Renaissance composer, William Byrd, in All The Colours In The Air.

Three other concerts stand out as real must-sees, with advance booking recommended. In Carnival Of The Seasons (October 2), the Lewes-based, internationally-famed Red Priest will bring their swashbuckling virtuosity and compelling stagecraft to the music of Vivaldi, the flame-haired priest from whom they take their name.

"They leap about a lot," says Norburn of the baroque quartet, who will perform his Four Seasons as you've never heard them before in this family concert.

Then, on October 7, the singers of I Fagiolini will pair up with actors under the direction of English National Opera's John La Bouchardiere for The Full Monteverdi, a dynamic staged performance of Monteverdi's erotic madrigals, while the festival finale comes courtesy of The Tallis Scholars.

In Music From The Sistine Chapel (October 10, St Peter's Church), these leading exponents of Renaissance sacred music will make their first appearance in Brighton, with a programme including Allegri's famous Miserere.

Norburn's own group, Mediva, invite us to a Fiesta! at the Medieval court of King Alfonso the wise on October 3. But, in terms of innovation and audience diversity, she hopes October 9 will prove the biggest success.

On this day, three concerts will explore the spirit and daring of early music, culminating in Extempore II, a Medieval/jazz crossover event between The Orlando Consort and jazz ensemble The Perfect Houseplants.

"No one's pretending they had percussion and pianos in the Middle Ages and jazzed it up," Norburn says, "but the original performers were all big improvisers. This one should finally persuade people that early music isn't all stuffy academics."

With ticket sales already up 200 per cent on last year and audiences coming from as far away as South Africa, Norburn and her co-director Deborah Roberts certainly look like having a popular hit on their hands. Just don't call them the Medieval Babes.

For the full Brighton Early Music Festival programme, log on to www.bremf.org.uk and keep an eye on Argus listings for daily concert details. Concession prices include 12-25-year-olds. Accompanied children under 12 go free.

Starts: Various times, Tickets: £4-£16, Tel: 01273 709709