After taking a long break from recording new material, Sigur Rós' sixth album, Valtari, is a welcome return for the Icelandic soundscape pioneers. Their previous album Med Sud I Eyrum Vid Spilum Endalaust had been their most intimate and cheerful record to date with songs that could actually be called "songs" and the band stripping their sound down to the point where you could almost pick out individual instruments in the mix. It appears that singer Jonsi took all the sunshine and most of the pop song structure away for use in his solo career, because Valtari is a return to the epically somber and sonically all-encompassing approach the band perfected on their first few albums. Filled with giant washes of sound bathed in reverb, echoing keyboards, smears of strings, and massed backing vocals, the album ebbs and flows from giant crescendos to heartbreakingly intimate moments with Jonsi's otherworldly voice riding the waves like a mythical dolphin. Each song creates its own insular world of atmosphere and emotion that can be so intense that when they end (usually after a solid six to eight minutes), the silence makes it feel like you've been yanked harshly out of a reverie. It's a shocking sensation but it speaks to how completely the band is able to transport the listener out of the day to day and into a magical realm. As is usually the case, it's a realm of graceful melancholy that comes across as a bit gloomy, until Jonsi begins to sing in his angelic croon, that is, and you are lifted. On the surface, Valtari may seem like a step back for the band, but instead of just retreading the past, the album is one of their best; a refined display of their musical power with breathtaking dynamics and enough emotion to flood an ocean.