Daniel Lopatin's score mixes electronica and opera in menacing fashion that keeps viewers' blood pressure high, but also contributes to the strange magic the Safdies are working. There's a distinct touch of the supernatural to their vision, transforming Howard's tale into a fable of sorts. In the opening moments, the camera dives into the beauty reflected in the black opal and emerges out of Howard's intestines, the otherworldly colors mixing with the grotesque guts. It's a good symbol for the rest of the movie, which finds euphoria in trashiness.
Part of the pleasure of Uncut Gems is in the Safdies' approach to casting, which is consistently surprising, mixing veterans like Sandler, Menzel, Eric Bogosian, and Judd Hirsch with newcomers like Julia Fox and celebrities doing spins on their lesser-shown personas. Garnett's role is crucial to the plot, while The Weeknd, a.k.a. Abel Tesfaye, has a showy scene, as The Weeknd.
In the end, it all comes back to Howard, who Sandler makes frustrating and captivating in equal measure. He's not lovable, but you also can't not root for the guy. At the TIFF premiere, just before the movie started, someone in the audience screamed: "Oscar for Sandman!" After seeing his performance in Uncut Gems, I don't think that would be such a bad idea.