Peter Margasak wrote a sharp, context-rich Soundboard capsule for this Saturday's Pharoah Sanders and Chicago Underground Duo show at the Promontory. In his capsule Peter mentions an album I didn't even know existed, Spiral Mercury, a recording of a concert in Lisbon featuring a sextet that includes Sanders and cornetist Rob Mazurek. I'd include a track off of that for today's 12 O'Clock Track, but I can't seem to find any clips online. My personal favorite Sanders performance is off the 1973 (but recorded in 1969) album Izipho Zam, but at nearly a half-hour long it is way too intense to post here. If you're curious, you can hear it via a quick Google search (it's an expensive import). So to get you excited for Sanders's first appearance in Chicago in more than a decade, here's the title track off of Sanders's 1971 album Thembi. This particular cut also boasts Cecil McBee on bass, Clifford Jarvis on drums, James Jordan on cymbal, Michael White on violin, and none other than Lonnie Liston Smith on piano; everyone plays various percussion throughout. "Thembi" is an example of a gentler, shimmering side of Sanders's playing, but it offers glimpses of the occasions when his saxophone ventures off into dissonant extremes. I can't tell you what to expect out of Saturday's performance, and that's a testament to just how unpredictable and illuminating Sanders's music can be.