On the surface, San Francisco’s the Stone Foxes are a hard-rock band in the same vein as the Black Keys with a tinge of psychedelia. Their new single “Psycho” starts off with crunchy guitar chords and reverby, distorted vocals on the refrain, “She’s a psycho!” But keep listening, and the Stone Foxes start to sound more and more like Pig Pen-era Grateful Dead (mid ’70s), a fitting Bay Area lineage. The group’s cover of Slim Harpo’s “I’m a King Bee” is arguably their biggest hit thus far, featured in a commercial for Jack Daniel’s Tennessee Honey. Songs like their original “Stomp” show off the depth of this band’s clever instrumentation and historical music knowledge. Each member takes a turn on lead vocals over a percussive track consisting of nothing more than hand-claps, a bit of slide guitar, and the backing harmony of their bandmates. There’s no doubt that the Stone Foxes are a rock ’n’ roll band. These guys play until their ears bleed. But don’t pigeonhole the group, or you’ll miss some seriously bluesy undertones.