With Mastodon's fourth full-length album, the Atlanta-based band made the leap to progressive metal that they hinted at with their previous album - 2006's Blood Mountain. Crack the Skye is also a full-blown concept album, telling the story of a paraplegic whose soul, through astral travels and divination, ends up in the body of Rasputin. On paper it reads like something that only metalheads and basement-dwelling dungeon masters would enjoy. But the end result - seven tracks of intricate musical arrangements coupled with flat-out hard rock - is the most accessible metal album of the decade and, simply put, the best album of 2009.

By now, we've had almost an entire year to let Merriweather Post Pavilion sink in, as it was one of the first highly anticipated releases of 2009. Here's what we now know: Animal Collective has accomplished something exceptional – Panda Bear, Avey Tare, and Geologist managed to make both their most accessible and finest album, and they did it without alienating their core fan base. Plus, they did it without Deakin, the band's primary guitarist, who took the album off.

On this, their ninth studio album, J Mascis and his Dinosaur Jr. bandmates prove that if there is anything they have learned in their 25 years of being a band (putting aside the nine-year hiatus/breakup from 1997 to 2005) it is that being loud is not enough. Notorious for being one of the most deafening live bands in the world, the true greatness of Farm lies behind the walls of feedback and distortion with its downright solid songwriting.

It's hard to believe that just a few years ago, Sunset Rubdown was merely Spencer Krug's solo project. With the release of Dragonslayer, Sunset Rubdown – now a five-piece – is threatening to turn Wolf Parade into a side project for Krug. While Krug is still unquestionably the driving force behind the album, the eight fantastically epic tracks benefit from the increased vocal role of Camilla Wynne Ingr, the band's "jane-of-all-trades," who provides a perfect counterbalance to Krug’s frenetic keyboards and spastic warble.

If you weren't a fan of Phoenix before hearing this album, you might not know that this French foursome has three fantastic prior albums and even scored a minor hit with "Too Young," which appeared on the Lost in Translation soundtrack. Building on their solid track record, Phoenix took a significant step forward with the release of Wolfgang Amadeus Phoenix. It's an infectious, upbeat indie pop album that really couldn’t be any better, and it has rightfully broken the band to the mainstream public.

When Magnolia Electric Co. touring bassist Evan Farrell died tragically in late 2007, frontman Jason Molina wrote his latest masterpiece in tribute to his fallen friend. Recording with frequent producer Steve Albini, Molina left behind the Crazy Horse sound that populated the past few Magnolia Electric records in favor of songs with a more minimalistic country/western feel (with accompaniment from slide guitar, dobros, horns, and the like). Josephine is an album about loneliness, dislocation, and heartbreak - themes not uncommon in Molina's work, but here feeling even more authentic due to the real life sorrow that contributed to the making of this album.

On the beautifully haunting follow-up to her critically acclaimed debut Marry Me, multi-instrumentalist Annie Clark (who performs under the moniker St. Vincent) has no problem avoiding a sophomore slump. Daringly creative and ambitious, Actor blends Clark's soothing voice and thoughtful yet seething lyrics with striking instrumentation that begins with her fantastically unique guitar work. Notably, Clark, the former touring guitarist for The Polyphonic Spree and Sufjan Stevens, didn't write Actor's songs on guitar or piano, but instead used Apple's Garage Band software to write and arrange them. Regardless, the result is an engrossing album that demands repeated listens.

Album, which The Top 13 picked as the best debut album of the year, offers a fresh take on pop music, one infused with noise rock, new wave, punk, and psychadelia. And this is a perfect album for a summer day, one that perhaps borrows a bit from the Beach Boys, but does so without in any way sounding derivative. Indeed, Girls have delivered right out of the gate an exceptional slice of bright indie pop that is unlike any of the other albums on this list.

This is a familiar story in the music industry: An underground band with a loyal following gets scooped up by a major label, records their next album with a big-time producer, and starts gaining new fans while the old fans are left wishing nothing had changed. Many will say this is the Avett Brothers' best album and just as many will argue that the gloss applied by uber-producer Rick Rubin is the beginning of the end of a great run. No matter which side of the fence you fall on, this album has some undeniably great songs, such as "The Perfect Space," "Slight Figure of Speech," and the epic title track.

With Face Control, the second full-length release from Wolf Parade co-leader Dan Boeckner and his wife, Alexei Perry, the Handsome Furs no longer sound like a side project, as they did on their debut. Whereas Plague Park was an intriguing but ultimately sparse and moody album that never quite reached its potential, Face Control offers a much fuller musical experience: Boeckner is at his best both lyrically and on guitar and Perry adds spirited work on the synthesizer and drum machine. While many of the tracks (inspired by the band's travels in Russia) stand out, "I'm Confused," for which the Furs made a fantastic zombie video, is the album's highlight.

Grammy nominated and referred to by Spin as the "alternative pop album of the decade," It's Blitz is somewhat of a departure for this punkish rock trio. Credited for their debut album, Fever to Tell, with contributing to the resurrection of the New York rock scene, most of Nick Zinner's shredding guitars are absent here, replaced by a heavy dose of synthesizers Zinner himself provides. The result, as always anchored by Karen O's manic and rangy vocals, is a revelation. The band's successful reinvention cements its status as one of alternative music's most important bands and it was rewarded with headlining gigs at a number of major summer music festivals.

With Led Zeppelin bassist John Paul Jones, Nirvana drummer Dave Grohl, and Queens of the Stone Age singer and guitarist Josh Homme comprising the band, it's no surprise that the self-produced debut from Them Crooked Vultures was one of the most eagerly anticipated albums of the year. The self-titled album doesn't disappoint. While it certainly sounds more like a Queens of the Stone Age release than anything ever recorded by Nirvana or Zeppelin, collaborating with masters like Jones and Grohl has brought out the best in Homme. This is a fantastic rock album.

With its debut album clocking in at barely 35 minutes, this Vancouver duo doesn't have all that much time to make an impression. But the eight songs on Post-Nothing do just that. Long-listed for the prestigious Canadian Polaris Music Prize, this album combines first-rate post-punk noise and garage rock in a fury of hazy guitars and tag team vocals. The lyrics are simple – mostly about girls and getting wasted – but they more that suffice to complement the barrage of sound created by only drums and the guitar.