Lady Gaga announced the dates and venues for the summer leg of her continually expanding Monster Ball tour today (Mar. 15), which will see the pop star headlining arenas throughout North America for the first time. The trek begins June 28 in Montreal and continues until Sept. 19 when it wraps up in Raleigh N.C. The first dates of the tour - including a July 6 stop at New York's Madison Square Garden - go on sale March 19.

Missing from the itinerary announced today is Lady Gaga's as-yet-unofficial headlining appearance at the Lollapalooza festival in downtown Chicago, although the dates of the festival, Aug. 6 - 8, remain open on the schedule.

Although Gaga's 2009-2010 North American tour was also dubbed the Monster Ball, the pop star promises an expanded production built to suit the larger venues. "It's still called Monster Ball, but it's more of a musical and less of a concert," Lady Gaga said in a February interview with KIIS-FM's Ryan Seacrest. "It has a New York theme, it's a story, and the story is that me and my friends are in New York and we're going to the Monster Ball, and we get lost."

There are looks of confusion all around Madison Square Garden.

It's a bitterly cold February night, and an impressively diverse crowd has packed the arena to see the Black Eyed Peas. But before the group takes the stage for two hours of singing, shiny-outfit wearing and product placement, a DJ booth rises from the floor, manned by a cheerful, bouncy, floppy-haired Frenchman. While the audience is initially befuddled, the second the music starts, recognition lights up their faces, and they begin to dance, for the manically jumping man behind the booth is David Guetta, the DJ responsible for some of the biggest hits on pop radio.

After his short set, Guetta returns to close the show with the Peas, standing behind turntables for their biggest hit, "I Gotta Feeling," which he produced and co-wrote. The track topped the Billboard Hot 100 for 10 weeks in the summer of 2009 and is still in the top 20 months later. It has sold more than 5 million downloads and has appeared in ads for Target and the Winter Olympics, as well being adopted as the official song of the Portuguese national soccer team.

Reunited Irish boy band Boyzone's "Brother" (Polydor/Universal), named for the memory of their colleague Stephen Gateley, who died suddenly last October, debuted at the top of the new U.K. album chart. South London rapper Tinie Tempah's "Pass Out" (Parlophone/EMI) started a second week at No. 1 on the singles survey.

The Boyzone album had been behind Gorillaz' "Plastic Beach" (Parlophone/EMI) earlier in the sales week, but forged ahead by the end of Saturday night with total sales of 101,000, according to the Official Chart Company. "Brother," which features Gateley's last recorded vocals, was completed by his Boyzone bandmates in tribute to "Steo," as they knew him.