Just how much mileage can you get out a single loop? Both Pablo Cahn and Cesar Merveille seem to know the answer. If only these guys had turned their talents towards automotive engineering, we might have vastly more fuel-efficient cars by now, and an end to global warming. But we can take consolation, at least, in the heat they bring to the dancefloor.Cahn and Merveille worked together on Cadenza 39; here they each take a side in a friendly contest to see who can go deeper. Right from the get-go, Pablo Cahn’s “Elle” is one of those “yeeeeeah” kind of tracks, frequency-rich and deeply satisfying, with pumping chords as juicy and marbled as slabs of meat. It moves with a skip in its step and a coy little swing that makes the track seem quicker than it really is-perfect for ratcheting up the energy level in any set. For 11 minutes, it just builds and builds and builds atop a single set of chords, with nimble saxophone riffage, rushing harmonic waves, and almost subliminal voices; Cahn works the filters with extreme finesse, leaning into the resonance to create chest-thumping bass.Cesar Merveille’s “FK” begins with a bright, feathery loop of acoustic drums and guitars, maybe even banjos, and lets it spin blissfully, over and over. A sparse piano melody takes the lead, sweetly detached, as though lost in daydreaming; it’s answered by a saxophone solo that drives the momentum joyously forward. It’s a rich, full production, gorgeously textured, but it’s never too full: Merveille balances the elements with rare restraint, drawing out the drama and bringing us gently back to earth at the end.