George Michael is gearing up for his first tour of the United States and Canada in 17 years, opening a multi-city “25 Live” tour in San Diego on June 17. The tour is scheduled to wrap in Sunrise, Fla., on Aug. 3. Other stops include Atlanta, Las Vegas, Phoenix, Los Angeles, Seattle, Chicago, Dallas, Houston, New York, Boston, Toronto and Montreal. Michael sang in the ’80s pop group Wham! before embarking on a successful solo career. He’ll release his greatest-hits album “Twenty Five” in the U.S. on April 1. Michael’s summer arena tour of the U.S. will be his last, because he no longer wants to play shows to large audiences. He admits he is ready to scale down the size of his concerts and play more intimate venues in future. He says, “I don’t want to do anything on this scale again. No more stadiums. I’d like to be the Tony Bennett for my generation.”It’s the end of a certain era, and I’m not sure how much I really want to be a part of what’s next. So, it’s a kind of a way of saying thank you to everybody before I move on.”