Drone Maintenance is the third full length work of progressive drone conjured by Black wolf goat, which is the solo vehicle of guitarist Darryl Shepard (Black Pyramid, the Scimitar, Hackman, Milligram, Roadsaw). The previous two outings, ?Dragon wizard sleeve? (2010) and ?Dronolith? (2011), established Shepard's modus operandi of looped guitar parts, building and layering upon each other, to create compositions of dense distortion, delicate lines, as well as purely ambient pieces.