Arca: “Mutant.” Alejandro Ghersi, a London-based Venezuelan who produces electronic music under the non de musique Arca, does not do pretty. Gritty, grimy, crunchy, crusty and downright filthy, you bet. Pretty, no. Yet if you can accept the idea of finding a kind of awful beauty in, say, an earthquake, or in a volcanic eruption, then “Mutant” might be for you. And it rocks, in both the geological and musical senses of the word.

Ólafur Arnalds & Nils Frahm: “Collaborative Works.” If your taste for electronica also extends to the gentler, mesmerising sub-genre known as “ambient,” then you’ll find rich pleasure in this 2-CD collaboration between two prolific stalwarts of electronica, Iceland’s Ólafur Arnalds  and Berliner Nils Frahm. The first CD — really three EPs gathered onto one full-length — is a “collage of our studio experiments of the past,”tossed off when Arnalds and Frahm would get together between gigs for rest and relaxation. The second, “Trance Frendz,”consists of improvised duets, both acoustic and electronic, performed last July in a Berlin studio following the sessions for a promotional video for the first CD. They had me by the first note and didn’t let me go until the last; then again, I’m a sucker for such stuff. You? Here’s a playlist of CD1: