Credit: Michael Becker/PictureGroup/FOX

Need Gaga tickets? There's an app for that! StubHub, the tickets-for-everything purveyor, has gone mobile, making it easier than ever to score seats to the hottest events. One concert on our must-see list? Lady Gaga's Monster Ball Tour, which kicked off its North American leg last night in Montreal. To celebrate the launch of their app, StubHub is giving Twitter followers four chances to win a pair of free tickets (transportation and accommodations NOT included) to see her live.Just follow @InStyle on Twitter, be the first to answer a Gaga style trivia question posted at 3 p.m. EST (once daily, Tuesday through Friday) and you’ll be one lucky little monster. You can find all of the answers to our questions in this gallery, so start studying now! We’ll give away 2 tix to her New York City show today, Dallas on Wednesday, Los Angeles on Thursday and Chicago on Friday.

Open only to legal U.S. residents age 21 or older at the time of entry. Void where prohibited by law. Limited to one entry per Twitter account per day. The first person to post the correct answer to the question each day on @InStyle will receive two tickets to the Lady Gaga concert in the specified city (ARV $200). Sponsor(s) not responsible for any damage to computer equipment related to participating in this promotion. Items being distributed are not transferable or redeemable for cash. Consumers who obtain items are responsible for any and all taxes. Promotion begins at 2 p.m. ET or EST on 06/29/2010 and ends at 3 P.M. ET or EST on 07/02/2010. InStyle will contact the winners by Twitter Direct Message on or before 07/02/2010. Each winner must submit his or her full name, working telephone number and mailing address or their entry may be disqualified. Employees of InStyle, Time Inc., StubHub, or any related companies are not eligible to enter or win.