Bass player and singer Rob Derhak said in a letter on the band’s website Monday that he was diagnosed early last week with oropharyngeal cancer, the oropharynx being the middle part of the throat.

“Although I’d known something wasn’t quite right for a while, I wasn’t expecting to get this news,” he wrote. “The prognosis is good, and the survival rate is high. Unfortunately the treatment will be rough on my body, and my voice.”

The progressive, improvisational rock band plans to play three scheduled concerts at music festivals in New York City and Virginia. After that, Derhak said he will be “out of commission for the foreseeable future” after his treatments begin in early August.

Moe. rose from Buffalo bars to touring the world, headlining music festivals and playing at New York’s Radio City Music Hall on New Year’s Eve in 2006 and 2007. They’ve hosted their moe.down festival in Turin, near Lowville, every summer since 2000.

Rob Derhak of moe. sings on June 29, 2010, at the Waterhole in Saranac Lake. (Enterprise photo — Lou Reuter)

They also have a strong presence in the Adirondacks. For two years they hosted a winter music festival called snoe.down in Lake Placid. In 2006, featuring fellow jam bands Assembly of Dust, Tea Leaf Green and the Gordon Stone Band. Snoe.down returned in 2007 with Little Feat and the Disco Biscuits. Although it brought about 4,000 people to the Olympic village, village police criticized those visitors’ drug use after making several arrests. The state Olympic Regional Development Authority declined to host the festival in 2008, mainly citing the demolition and construction to add a convention wing onto the Olympic Center. In 2009, moe. hosted snoe.down in Vermont.

In late June 2010, moe. play to a packed house at the Waterhole, a bar and live music club in Saranac Lake.

Band members’ side projects have performed locally as well. Floodwood, featuring moe. drummer Vinnie Amico, performed a free concert Tuesday night at Mid’s Park in downtown Lake Placid, part of the Songs at Mirror Lake Music Series.

Moe. performs on March 23, 2007, in the Lake Placid Olympic Center’s 1980 Rink in the second and last year of the band’s snoe.down music festival. (Enterprise photo — Lou Reuter)

Bass player Rob Derhak of moe. performs on March 18, 2006, in the Lake Placid Olympic Center’s 1980 Rink in the first year of the band’s snoe.down music festival. (Enterprise photo — Lou Reuter)

Bass player Rob Derhak and drummer Vinnie Amico of moe. perform on June 29, 2010, at the Waterhole in Saranac Lake. (Enterprise photo — Lou Reuter)