If you're at all familiar with Underworld's "Second Toughest In the Infants" LP from 1996, you'll know the driving trancey track "Rowla"; If you are lucky enough to own the "Pearl's Girl" EP, you'll find a track called "Cherry Pie" that starts with the same 5-note pattern and sounds, but quickly turns into something entirely different; urgent quelches and atmospheric pads are layered udner a barrage of beats.
And in listening to the 1996 shows (most recently the Quartz , Glastonbury and Reading summer festivals) you'll often hear these two tracks mixed seamlessly and epically into a good 15-20 minutes of bliss/aggression, depending on how you hear the world.
As I've mentioned, the 1996 shows have a rather fixed setlist, in comparison to the experimental jams of 1994-95. It could be a consequence of festival audiences, where you play the more recognizeable tracks at the expense of some deep cuts. But each performance reinforces the impression that nothin within the song is static - Underorld stretch these tracks out with some lovely beat-heavy passages, include child-like vocal samples, and generally showcase why they have been described as an improvisational electronic band.
Case in point: "Rez/Cowgirl" from the Reading Festival. Yes, these two tracks are typically played side by side, and I'd venture that they are among the most commonly performed tracks in the UW canon, one or both making an almost-nightly appearance. They are always jubilantly performed (in more recent years, Karl Hyde has taken to singing "Celebrate! Celebrate!" during the synth breakdown). In 1996, though, the mixed track was a bit fresher, and at Reading it is a 16:44 monster that grows from the twinkling pattern of Rez and ends with Hyde and the band triumphant before a crowd wanting more.