In celebration of the 25th anniversary of its hugely successful, highly irreverent and frankly hilarious animated sitcom South Park, Comedy Central booked two nights at Denver's iconic Red Rocks amphitheater last weekend and invited Primus - who wrote the hit show's theme tune - and Ween, who appeared in 1998's popular Chef Aid episode in the show's second season, to pay tribute to series creators Matt Stone and Trey Parker and some of the show's most iconic and memorable songs.
What Parker and Stone didn't know in advance was that Primus frontman Les Claypool had also secretly extended an invitation to Rush duo Geddy Lee and Alex Lifeson to join the party too on August 9 and 10.
Welcoming the prog rock legends onstage, Claypool revealed that he'd nagged life-long Rush fan Stone into learning the late Neil Peart's drum parts on the Canadian band's 1977 single Closer To The Heart so that he could sit in with Primus to cover the song: the idea seemed perfectly logical given that Primus have been performing the song's parent album, A Farewell To Kings, in its entirety on tour.
The look on Matt Stone's face as Claypool says "He had no idea that we were dropping this on him" is just priceless.
Watch fan-filmed footage, courtesy of YouTuber King Clit Commander, below:
A full version of the performance, filmed by YouTuber The Stallion Mang, can be viewed below, starting around the 9 minutes and 10 seconds mark.
The brace of concerts also featured Ween performing Kyle's Mom's A Bitch, and Primus performing the evergreen America, Fuck Yeah.