Citing medical issues with lead singer John Popper, Blues Traveler has canceled all of their concerts through September including their Friday, Sept. 14, show at the 17th annual Deadwood Jam.

Blues Traveler will be replaced by Colorado-based Big Head Todd & The Monsters.

No immediate information is available as to the extent of Popper's medical problems, but the issue left the Deadwood Jam committee scrambling to find a replacement for the Friday night show.

Big Head Todd & The Monsters is best known for hits such as "Bittersweet," "Resignation Superman" and "Broken Hearted Savior."

Big Head Todd & The Monsters will perform with the Drew Davis Band and Solution.

"Big Head Todd has become a part of our Jam family, and we can't thank them enough for stepping up and helping us out in our time of need," Joe Hamm, Jam chairman, said.

Hamm said anyone who bought tickets to see Blues Traveler and would like a refund may call Black Hills Central Reservations at 1-888-838-2855.

The Saturday, Sept. 15, lineup remains the same, with DownLo, reggae by Djate, Melvin Seals and Friends, Ryan Shupe and the Rubber Band, The Fabulous Thunderbirds, Cracker, and Robert Randolph and the Family Band.

Ticket prices for Friday's performances are $20 in advance, $25 day of show.

Tickets for Saturday's full day of music are $25 in advance or $30 day of show.

A two-day pass is $40 before the Jam. Tickets are on sale by calling Black Hills Central Reservations at 1-888-838-2855 or 1-605-578-7702.