You’ve seen them at parties, lurking in the corner, waiting to engage in battle disguised as conversation. They’re indie rock know-it-alls, and no matter what band or musician you mention, they’ve got an opinion — strong and almost certainly negative — ready to ram down your throat. With Instant Expert, we offer preparation for these very situations. Each Thursday, in advance of your weekend carousing, we pick an artist and provide a quickie career overview, highlighting both prevailing critical opinions and the inevitable contrarian counterarguments. Even if you’re completely unfamiliar with the music, you’ll be able to bluff your way through and defend your indie cred. This week: Sigur Rós.

  • The Gist

    Sigur Rós were formed in Iceland in the mid-'90s. By the end of the decade, they released their debut album, a hit in their homeland. With famous fans like Radiohead supporting their second album, 1999's 'Ágætis byrjun,' the group soon rocketed to indie-cool status. Much love is heaped on the ambient, post-rock quartet for its long, atmospheric songs (often played on guitar with a violin bow, just like Jimmy Page!), which rank among the loveliest records of the 21st century. There's also the fact that all of the songs are sung in Hopelandic, a made-up language consisting of syllables and sounds and not a whole lot of real-world meaning.

    Kevin Winter, Getty Images
  • Critical Consensus

    Sigur Rós' second album, 'Ágætis byrjun' (which means "a good beginning") was originally released in Iceland in 1999. Within two years, British and U.S. music snobs were drooling over it too. It's easy to hear why: With long, trance-like songs like 'Svefn-g-englar' and 'Viðrar vel til loftárása,'  'Ágætis byrjun' is one of the most mesmerizing albums ever made. Seriously. Who cares if you can't understand a single word frontman Jónsi is saying?

  • Contrarian Counterargument

    None of the eight songs on the band's 72-minute follow-up to 'Ágætis byrjun' have titles. The album doesn't even have a title, just a pair of parentheses, like this: '( ).' Artsy, pretentious and brilliant.

  • Counter-counterargument

    All that attention from Radiohead and their fans ruined Sigur Rós. They were at their best, and most Icelandic, on their 1997 debut 'Von.'

  • Whatever You Do, Don’t Say This

    The singer's just making s--- up as he goes along, isn't he?

    Karl Walter, Getty Images