Sweden’s Opeth has long been a fixture on the underground circuit, combining black- and death-metal atmospherics with old-school (read: 1970s) progressive song structures and melancholia. Now 11 years and five records into its career, the band is undertaking its first ever North American tour, logging roughly 40 shows in 50 days. Opeth isn’t taking many chances on this journey through the commercial promised land; it’s playing only the hits from each album, so as not to lose either the audience or each other. After all, this is not only the band’s first North American tour, it’s also its first tour of any kind in five years.

This leap across the big pond has been made somewhat easier by the band’s new CD, Blackwater Park, which has benefited from better distribution and more promotion than any previous Opeth disc on this side of the Atlantic. For the first time, the band’s music can be found in mainstream shops, and Blackwater Park was the most-added record on metal radio the week of its release.

Vocalist/guitarist Mikael ร…kerfeldt, who keeps the progressive muse alive via his day job at a prog-rock specialist shop, is possessed of one of the few voices in metal that can capture the extremes of both the death grunt and the operatic soar. On Blackwater Park this voice is attached to Opeth’s least-layered but most musically advanced outing yet. ร…kerfeldt in fact openly admits that some of its passages can’t be reproduced live — not because of multiple tracking or other such studio trickery, but simply because the band was “lucky” to have nailed it once.

Opeth has attempted to create a unique atmosphere on Blackwater Park. The album’s aggression is derived not from speed or brutality but from a certain darkness and a sense of palpable menace, an impending invisible peril familiar to devotees of Ingmar Bergman films. But even as the band brings this heady brew to newly exposed masses, side projects already loom, with ร…kerfeldt in particular eager to bring to fruition some long-simmering collaborations.

Point being, if this sounds like your cup o’ jack, best go ahead and check it out now.