The Grandmothers name was first used by Preston, Gardner and the late Jimmy Carl Black back in 1980. This version of project has been going in various forms since 2002, with the most recent incarnation also including percussionist Christopher Garcia and guitarists Robbie "Seahag" Mangano and/or Miroslav Tadic.
Updated, 4:25 p.m., 6/28/12: The ORH's Erica Durbin was kind enough to respond to an email and clear up the confusion about the band's lineup for this tour; it will be Brock, Preston, Fowler, Garcia and Tadic.
Ticket for the the Grandmothers of Invention at the Old Rock House are $20 in advance, $23 day of show, and go on sale at 5:00 p.m. tomorrow, Tuesday, June 19. The ORH also is offering a VIP ticket for $40, which includes "a meet & greet prior to the show with autographs, photos & a discount on merch."