Gerard Malanga is the ostensible star of Vinyl, the delinquent who breaks the law (all the laws) and must be forcibly reformed. He spends a lot of time posing and dancing and occasionally lifts weights or shoves someone around. As far as what passes for acting, he holds forth in the usual Warhol manner, i.e. a vague gesture at 40s-50s B-movie style. Sure, he would fit in pretty well in the background of Motorcycle Gang or Dragstrip Riot, but his stilted line readings would likely prevent him from doing much more. (Stop trying to make "scum baby" happen, Heather!)
Edie says nothing, but she's the center of attention thanks to sheer star quality... okay, and a little help from screen position. However, she gives a clinic in how to be present in--and even dominate--a scene without technically doing or saying anything by absorbing everything, reacting to everything. (When i recently made a brief and weird return to the stage, i had a good 10 minutes of "nothing" at one point, and Edie in Vinyl was inspiration for how to handle it. Also Marlene Dietrich in anything.) In a room full of people giving attitude, presenting themselves in this pose or that stance, she just is.
Eventually, Malanga gets ranted at by the cop and worked over the the sadists and everyone drinks plastic-cup cocktails and chainsmokes while someone plays records in the background. And that's part of what makes Vinyl interesting: There are always several things going on at once--if the foreground monologue bores you, there's always the background dancing, or someone getting fucked with or fucked up over on the side or whatever Edie is doing.
Intermittently, they give up on the dialogue and Malanga frugs frantically in his tight white hustler jeans as the "cop" leans back in his office chair and leers. Sedgwick sways back and forth, weaving one eloquent arm. In the background, another guy in white jeans roughs up a shirtless man in a gimp mask while two other men watch dispassionately. As everyone drifts off into their own little bubble of vice and bliss, it's like the after-hours of countless drug-dipped downtown Manhattan parties.
Along with being a fine illustration of what Andy Warhol's famed Factory must have been like on a good night, Vinyl is a record of that weird 60s moment halfway between beatnik and hippie. Today when people talk about "underground," it's just another buzzword for your Facebook/Tinder/marketing profile. (No one knows what "poseur" or "sellout" mean either.) but Vinyl is a relic of a time when the edge really was a place that few people saw and even fewer actually went.