It seems Grails have officially bridged the gap between Led Zeppelin and Ravi Shankar with Burning Off Impurities. The experimental quartet’s fourth album is a giant step ahead of its instru-metal (yes, it really is a genre) contemporaries (Explosions in the Sky, Envy), as it relies less on layers of epic, post-rock guitar, and more on whispering ambience, rhythmic guitar riffs, winding feedback, and plenty of textured delay. This slight shift might throw fans, but since Grails have a history of making left-turns with their releases, perhaps one shouldn’t be too surprised.

In addition to its newfound hallucinatory revelations, Grails are the embarking on a tour with Japanese labelmates Mono and World’s End Girlfriend. Grass smokers’ and patient listeners’ summers just got that much brighter.

Burning Off Impurities is out April 24, 2007 on Temporary Residence.

1. Soft Temple
2. More Extinction
3. Silk Rd.
4. Drawn Curtains
5. Outer Banks
6. Dead Vine Blues
7. Origin-ing
8. Burning Off Impurities