Justin Timberlake stepped up his return to the forefront of pop music Friday with news that he\'ll team up with Jay-Z this summer for full-scale concerts in a dozen major North American cities. In a statement, event promoters Live Nation said the duo -- who performed together during the Grammy awards earlier this month -- will kick off a \"Legends of the Summer\" tour on July 17 in Toronto. Gigs in such places as New York, Boston, Detroit, Miami, Chicago, San Francisco and Los Angeles are on the itinerary, with many scheduled to take place in legendary stadiums such as Fenway Park and the Rose Bowl. \"What are you doing this summer?!?!\" teased the 32-year-old pop idol on his Twitter account as the tour was announced. Timberlake\'s last big tour was in 2007, after which he put music on the back burner to pursue acting ambitions. This year has seen him play live at a pre-Super Bowl event ahead of the March 15 release of a new studio album. His latest single, \"Suit & Tie\" featuring Jay-Z, is at number nine this week on Billboard\'s Hot 100 singles chart.