Vocalist Josh Groban [ tickets ], who wraps up his inaugural headlining tour in May, is beginning to line up an extensive outing that will visit North American arenas and amphitheaters throughout the summer.

The 22-year-old Groban is proving to be a quick success story on the live-music scene, making the jump to large venues after just five months of sold-out headlining dates on the theater circuit.

The full summer itinerary hasn't emerged, but confirmed dates are shown below. Tickets for some of the summer dates will go on sale to the general public over this coming weekend, according to promoters. Members of Groban's fan club will have the first shot at tickets via Internet presales; details are posted at Groban's official website.

According to Groban's website, besides the cities below, the tour will also visit St. Louis; Interlochen, MI; Darien Center, NY; Camden, NJ; Mansfield, MA; Saratoga Springs, NY; Wantagh, NY; Bristow, VA; Pittsburgh; Columbus, OH; Chicago; Indianapolis; Houston; Kansas City, MO; Denver; and Portland, OR. Dates and venues for those cities couldn't be confirmed at press time.

Groban continues to support his sophomore album, "Closer," which topped The Billboard 200 album chart in January and has sold almost 3 million copies to date. The CD sits at No. 12 on the latest Billboard chart.

Groban made a splash in the music scene with his self-titled 2001 debut, which--on the strength of the single "To Where You Are"--has sold more than 5 million copies to date, according to Reprise Records.

His career got a huge push internationally when he performed at the closing ceremonies of the Salt Lake City Winter Olympics, a show seen by more than a billion television viewers around the world, according to Reprise.

"Closer" got a boost when he performed his song "You Raise Me Up" during the opening ceremonies of Super Bowl XXXVIII in January.