When Portland, Oregon's instrumental warlords Grails released Black Tar Prophecies, Vol. 1 in 2006, the members themselves saw it as a pivotal turning point in their sound. Still a relatively new group, they'd been shying away from their early odd hybrid of traditional Celtic modes and moody post-rock and getting more into the dubby, psychedelic soundscapes and increasingly aggressive playing that would come into full focus with that album. Delving into post-production techniques in a way they'd missed earlier on, the Black Tar Prophecies series became a vehicle for rampant experimentation for Grails, and Vols. 4, 5 & 6 shows the band easing into deeper phases of production-heavy exploration. The sprawling set is made up of 2010's Vol. 4, songs from a 2012 split with Pharaoh Overlord, plus three previously unreleased tunes comprising Vol. 6. Presented in the context of a full-length album, these disparate tracks actually work better than as piecemeal segments spanning several miscellaneous releases. The psychedelic and dub undertones that touch most of the band's catalog are there to some degree on almost every track, but they find themselves melded to cinematic themes as on the drunken minor-key dirge "Pale Purple Blues" or "Invitation to Ruin," which updates the dread-filled looming of 70's horror movie soundtracks with electronic beats and wobbly tape effects. Some material, such as the sultry piano and smooth-string faux R&B groover "Up All Night" or the bizarrely Baroque hip-hop feel of "A Mansion Has Many Rooms" point to the terrain explored by founding members Alex Hall and Emil Amos in their decidedly more sample-based side project Lilacs & Champagne. The 12 tunes run through these styles and many others, stopping in with moments reminiscent of everything from electric Miles Davis to Goblin to the courtly, acoustic Krautrock shimmer of Popol Vuh. The pieces never get too far removed from one another in their stylistic wandering, so instead of a random feeling, the production on these combined volumes of Black Tar Prophecies gels the various modes and methods into one cohesive, endlessly interesting stretch of instrumental sounds, ominous and brooding even in its most gentle moments.
AllMusic Review by Fred Thomas