Paul Allen’s Cannes bash is being talked about as one of the most rocking Film Festival parties this year. Guests, including Antonio Banderas and Jeremy Irons, danced until the early hours to the Microsoft co-founder’s band (in which he plays guitar) at Monday’s party. One guest told us, “Paul has a new band, and they are actually really very good — people were dancing until 4 a.m.” Also there were Cyndi Lauper, Ray Liotta, Tom Freston and Sony Pictures Classics’ Michael Barker and Tom Bernard. All braved bad weather to get onboard Allen’s 303-foot yacht Tatoosh, which was moved to a new mooring for the bash because of heavy swells and “to stabilize the boat.” The party-goer added, “Paul told the crowd, ‘I have got a funny song for you,’ then launched into ‘Purple Rain,’ poking fun at the bad weather.” Over at the Chopard bash, also on Monday, Sean “Diddy” Combs was walking around with a camera crew filming a documentary for his new network. He was there with Cassie, Andre Harrell and Angela Martini. Meanwhile, on the movie circuit, tongues are wagging about relative newcomer Jason Clarke. The actor holds his own against Tom Hardy, Guy Pearce and Shia LaBeouf in the Weinstein Company’s “Lawless,” which premiered in Cannes on Saturday night to a 10-minute standing ovation. Clarke will next be seen in Baz Luhrmann’s eagerly anticipated “The Great Gatsby” alongside Carey Mulligan and Leonardo DiCaprio.