Bespectacled and mustached, he gyrates in his underwear while tapping keys, punching pads, and looping every sound at his disposal. He looks like a fit version of Kip from Napoleon Dynamite and a ’70s porn star, the charisma and intensity of the former cranked up to match the unrepentant lasciviousness of the latter. This is Marc Rebillet, aka “Loop Daddy.” Both via simulcast live-stream and on stage, the 31-year-old Dallas native improvises songs based on conversations with his audience. Topics include but are not limited to “big booty” and “mushroom trip.” “Generally, I find songs having to do with ass or fucking do quite well,” Rebillet tells SPIN over the phone from his Manhattan apartment. With or without suggestion or approbation, he’d still be belting odes to ass and trying to fi...