Sigur Rós is the most famous--and best--synthesizer of traditional and modern Icelandic music. The mournful chanting of the country's Head Pagan(!), Hilmar Örn Hilmarsson, segues easily into their epic sound.
At a performance duplicated in the Sigur Rós concert film "Heima," the band plays with Hilmarsson. Artist Andy Goldsworthy would be proud of the stone marimbas created for the performance. Flat stones are collected and hit with a mallet to determine their sound. After a few octaves worth of stones are found, they're lashed to a resonating frame. This instrument, derived almost completely from nature, is wonderfully complex. ("Heima" has more on its creation than "Screaming Masterpiece;" I never wrote about that film.)
Ventures past the core "Icelandic" sound elude "Screaming Masterpiece." Attempts at punk, metal, and rap sound like third-generation xeroxes of better bands. There's a reason Sigur Rós, Björk, and múm are the most famous bands from Iceland--they sound like nothing else.