is aimed at 20- to 30-year-olds and will present visitors with highlights of new and live music. Seven curators, deemed by Pepsi to be "leading music artists and tastemakers", will decide what content goes on the site.
Joining Barat, formerly of the Libertines, and Harsh are Australian singer-songwriter Sam Sparro, pop band The Loose Cannons, grime artist Tinchy Stryder and musician Peyton.
Sparro said: "All the best music is on MySpace, but finding it is like a needle in a haystack."
Users can also post gig flyers and recommend new music to other users, via the Maxcast Radar section of the site.
Bruno Gruwez, marketing director of Pepsi UK, said: "Pepsi Maxcast is there to help people discover new and live music. It's a fully fledged interactive platform that opens up the world of leading artists and tastemakers to the public.
"It's a unique platform where people can engage with the best live music presented by our celebrity curators, and for bands to get their music featured."
Earlier this week Pepsi unveiled a new logo, part of a £700m global brand revamp.
It also plans to launch the Mountain Dew and Sierra Mist brands in the UK.