The title of this 20-track compilation is pretty self-explanatory. Instrumental rock with growling, distorted guitars is the main order of the day here, usually based around R&B-derived progressions, sometimes with smoky sax as embellishment. At its best that can be a great combination, but it's also prone to formulaic songs that don't have much going for them beyond the skills of the instrumentalists. You get some of both here, the clear king of this hill being Link Wray, represented by his searing minor 1963 hit "Jack the Ripper" and his lesser-known 1964 45 "Deuces Wild." The best of the rest, too, tends to be by the more familiar names (or at least the names most familiar to enthusiasts of early- to mid-'60s instrumental rock), like Jan Davis (with the ridiculous but menacing "Watusi Zombie"), the Fireballs, and Al Casey (whose 1963 recordings "Jezebel" and "Thunder Cloud" are heard for the first time on this CD). Some of the other tracks are more like period background music, though the Buddies' "Pulsebeat" is a pretty fair "Pipeline" sound-alike, and the inventive bluesy twang of a young Roy Buchanan can be heard on the Secrets' 1962 single "Twin Exhaust." There is a heap of rarities for collectors to savor here, but really, if you're looking for a killer album of this sort of thing, an entire compilation of Link Wray leaves this in the dust