Achieving longevity in the fickle world of pop music requires a boatload of talent and the ability to intimidate rival acts by steering really big boats into their beach houses. Get steamrolled by immutable music with today’s Groupon to Britney Spears’ Femme Fatale tour at Philips Arena on Sunday, July 17, at 7 p.m. Doors open at 5:30 p.m., and seats are assigned at pickup on a first-come, first-served basis. Choose from the following options:

• For $36, you get a seat in level 300 (a $59.50 value before fees, or up to a $70.85 value online, including all ticketing fees).
• For $58, you get a seat in level 200 (a $99.50 value before fees, or up to a $114.95 value online, including all ticketing fees).
• For $97, you get a seat in level 100 (a $175 value before fees, or up to a $192.50 value online, including all ticketing fees).