Few bands are as monolithic as Washington DC post-hardcore demigods Fugazi. For decades, they have been celebrated for their ethical convictions as well as the severity of their output. So it comes as “No Surprise” that the documentary about one of the best bands in the world would be one of the greatest music films ever made.

The documentary Instrument is a massive work, following Fugazi from their early days in the DC hardcore scene to the recording of End Hits, and it captures a side of Fugazi that runs counter to their reputation as self-serious punk monks—most notably that they lived in a house together with no heat, surviving on a Steady Diet of Nothing but rice. The film instead shows a group of guys who love making music and have a lot of fun doing it.

Likewise, the soundtrack to that film captures the same playful attitude—which isn’t a word typically used to describe Fugazi.

The tracklist of Instrument Soundtrack has no room for self-seriousness. The tracks are a mix of instrumental interludes, End Hits demos, and studio goofing (e.g., “Me and Thumbelina“). There are plenty of unreleased instrumental jams like “Lusty Scripps” and “Swingset,” all of which are unmistakably Fugazi. Interestingly, the more patient instrumental tracks like “Trio’s” or “H.B.” have a hushed, angular sensibility that is reminiscent of bands like Slint or June of 44.

The demo tracks from End Hits are particularly interesting. End Hits is perhaps their most cerebral record, featuring liberal use of studio tricks. But the versions that exist here are fairly straightforward. “Rend It,” which exists in the album as a desperate, manic plea, is practically an acoustic ballad. “Pink Frosty,” a complex, dub-reggae influenced track, appears here as a guitar jam without any overdubs. “Closed Captioned” on the other hand is even more experimental here than on the album, fading between different drum takes and beat machines almost chaotically. There’s also “Slo Crostic,” an alternate version of “Caustic Acrostic” that’s been so heavily rearranged it only barely resembles the released version. It’s a rare thing to see the creative process so intimately, and Fugazi’s creativity was rare indeed, so these demos are a treat.

The most celebrated track on here though is the Ian MacKaye piano ballad “I’m So Tired.” It’s the closest thing to a ballad the quartet ever did, and almost sounds Beatles-y—an aesthetic that Ian would carry on to his later project The Evens. It’s a brief track—it just barely fails to break the two-minute mark—but it is a rare gem.

Now, it’s no surprise that Fugazi is one of my favorite bands. They’re included in my personal Top Five, which is as far as I’ve ever quantified my tastes. But I’ve long hemmed and hawed over the thought of purchasing this soundtrack, believing it to be for completists only. But after watching the film—and realizing that I am a completist, actually—I realized just how essential it is. It likely won’t get too much rotation, but it is an important piece of my Fugazi collection.