Standing up for prog isn't as hard as it used to be. Later-vintage Genesis, Emerson, Lake & Palmer and Yes (apologies to the Professor of Pop) did make some of us defensive, did rightfully help ignite the punk backlash and does still provide my KPFA-mate Bonnie Simmons with fodder for giving me grief when I play Electric Light Orchestra on my radio show.
But such bands as Ghost, from Japan, Fern Knight, from Philadelphia, and Mushroom, from right here in the Bay Area, have freshened up the spacey and psychedelic qualities that drew us to early Pink Floyd, King Crimson and Soft Machine in the first place. 
And who's going make fun of Cluster? The seminal kraut rock band, formed as Kluster in 1970 by Dieter Moebius, Hans-Joachim Roedelius and Conrad Schnitzler, has maintained a certain insularity to ridicule over the past four decades. Part of it has to do with artistic integrity: the trio, with roots in Berlin's Zodiak Free Arts Lab, was much more an avant-garde experimental improvising unit than a pop band. Part of it has to do with the presumed corollary to integrity -- lack of commercial success.
Schnitzler left the band shortly after its founding, but Moebius and Roedelius have continued collaborating on and off since releasing the first two Cluster albums in 1971 and 1972. Although Cluster never became household name like Kraftwerk or Tangerine Dream, sessions with Neu!'s Michael Rother (as Harmonia) and Brian Eno, CD reissues of such classics as Zuckerzeit and Sowiesoso, and the recent appearance of a new live album, Berlin 07, have kept these avatars of space-rock and electronica on the radar of the Cluster cult.
Now the reunited Moebius and Roedelius are touring again and appear Sunday, May 25, at the Great American Music Hall in San Francisco, with Tussle, White Rainbow, guest DJs and free donuts. The show starts at 8 p.m.: Progheads, stand up and be counted.