Martina McBride [ tickets ] and Alan Jackson [ tickets ], whose previous co-headlining run proved to be one of early 2004's top-grossing tours, have lined up nearly 30 new shows together for late summer and early fall.

In a year where many concert promoters are bemoaning slow ticket sales, the McBride/Jackson pairing was a success story. The tour grossed nearly $25 million during the first half of the year, according to concert industry magazine Pollstar, with fans snapping up an average of about 12,500 tickets per show.

McBride continues to back last year's "Martina," her first new studio set since 1999's "Emotion." She co-produced the platinum-certified album with long-time collaborator Paul Worley, and recorded it at her new Nashville studio, dubbed Blackbird.

Last year, McBride picked up her second straight Country Music Association Female Vocalist of the Year Award. At May's Academy of Country Music Awards, she picked up her third consecutive win for Top Female Vocalist category, as well as the Humanitarian Award.

Jackson, a Georgia native, has become one of country music's most bankable acts over the years, and has sold more than 36 million albums since his 1989 debut, "Here in the Real World," according to his label. He was named the Country Music Association's Male Vocalist of the Year in 2003.

Arista Nashville has set a Sept. 7 release date for "What I Do," Jackson's 14th album. The set, recorded with Jackson's longtime producer Keith Stegall, features 14 new tracks, including the hit single "Too Much of a Good Thing."