From the opening atonal freakout from guitarist Greg Giinn, “Slip It In” continues Black Flag’s determined jump into the free-jazz-metal abyss. While the band began with its roots in the Southern California hardcore punk scene, they were determined to find a new heaviness that would merge Rollins’ dreams of Jim Morrison and John Coltrane with the band’s love for Black Sabbath and the Ramones. But no matter how possessed Rollins comes across — and on “Rat’s Eyes” he sounds plenty possessed — the show still belongs to Greg Ginn who simply tears up the album with one inspired and challenging guitar solo after another. The enthusiastic chug of “Black Coffee,” the bizarre struggle of “Obliteration,” the faux-metal crunch of “The Bars,” the deafening feedback of the hardcore revisit of “My Ghetto” and the epic boogie of the seven-minute “You’re Not Evil” comprise tunes that often slip under the radar but are among the most potent in the Black Flag catalog. The fact that this album appeared in 1984, only several months after My War, made it difficult for people to completely digest what was happening before their ears. With time, these tunes have gained in strength.