The Mars Volta recently launched pre-orders and quickly sold out of their massive, very expensive, and very limited new box set La Realidad De Los Sueños, but as mentioned, they'll be putting out Landscape Tantrums, "the unfinished original recordings of De-Loused In The Comatorium," as a digital release on April 23 via Clouds Hill. Today, they've released the first song from that album, an early version of "Inertiatic ESP." This version does indeed sound like an unfinished demo, but it's also cool to hear how close this is to the album version, even in this raw, unpolished form. Listen below.

We recently included De-Loused In The Comatorium as one of 15 albums that shaped progressive post-hardcore in the 2000s, and here's what we said about it:

At The Drive-In had already pushed post-hardcore in a more progressive direction on their final pre-reunion album, 2000's immortal Relationship of Command, but when vocalist Cedric Bixler-Zavala and guitarist Omar Rodríguez-López started their next band The Mars Volta, they went full-on prog, and pretty much became the first post-hardcore band to do so this blatantly. The energy and volume of their previous band still informed the songwriting on The Mars Volta's 2003 debut LP De-Loused in the Comatorium, but so did the mind-melting prog riffage of King Crimson and the psychedelic Latin jazz-rock freakouts of Santana. The Mars Volta almost singlehandedly introduced the influence of those bands into the contemporary punk scene, and they did them justice too. This wasn't a case of imitation; De-Loused in the Comatorium felt as groundbreaking in 2003 as In the Court of the Crimson King and Abraxas did three decades earlier, and like those albums, it still sounds timeless today. Cedric had already honed his singing voice by Relationship of Command, but he was belting it on this album in a way you never would've guessed he could in the ATDI days. Likewise, Omar was fleshing Relationship of Command out with dizzying lead guitar, but on this album he's a straight-up guitar hero. And matching the over-the-top prog of the instrumentation is the fact that it's lyrically a concept album based on an accompanying short story about a man who overdoses and enters a coma. The whole thing is as excessive and flashy as '70s rock ever get, but it still hits as hard as Cedric and Omar did in their previous lives as hardcore kids. The Mars Volta would get more progressive and less post-hardcore as their career went on, but De-Loused will always remain one of the first, best, and truest examples of 21st century progressive post-hardcore.

Read the full list here.