Elliott Smith was not Tupac. He recorded a lot during his lifetime, but in the decade since his death, a relatively paltry amount of unheard material has made it out of his vault. After From a Basement on the Hill—the album Smith was working on when he died, issued posthumously in 2004—and the two-disc compilation New Moon, it didn't seem like there was much left to excavate.

But in the process of making Heaven Adores You, the excellent documentary about the adored singer-songwriter's life, the producers turned up a trove of undiscovered music—demos, sketches and alternate versions, stretching as far as back Smith's teenage years, which, taken together, provide a glimpse into the creative process of one of the most revered artists of his generation. On Feb. 5, those songs, along with a handful of familiar studio versions, will be released as a companion soundtrack to the film.

You can listen to the whole thing now NPR's First Listen.

We asked Kevin Moyer—the soundtrack supervisor and an acquaintance of Smith's from when they both attended Lincoln High School in Portland—for a track-by-track guide.

1. "Untitled Guitar Finger Picking," 1983

This one is young Elliott recording with his friends in Texas at a sleepover. Elliott plugged his electric guitar straight into a four-track reel-to-reel tape recorder that Steve's dad had. Later on the same tape there is a recording of Elliott performing "Soul Cake," a traditional English folk song recorded by Peter, Paul and Mary which uses the same finger-picking style.

2. "Untitled Melancholy Song," 1993

This unreleased song comes from the same cassette as "Last Call" during the Roman Candle era. I love this one—all the changes throughout. It has so many different parts that we could have used this anywhere in the film really, and we only used a small part of it. I included it on the soundtrack because I think the whole thing is worth hearing. Also note that the soundtrack's opening two recordings are unfinished instrumentals that represent a world of music where Elliott's voice is missing, and that is really fucking sad.

3. "Don't Call Me Billy" (early version of "Fear City"), 1993

This unreleased song would eventually evolve drastically into the song "Fear City," which was recorded for the Either/Or sessions but appears on the posthumous release New Moon. But this version is very different and comes from a cassette that also included "Carl's El Camino," which was another early song that would eventually become a different released song called "Kiwi Mad Dog."

4. "Christian Brothers" (performed with Heatmiser), 1995

This is Elliott with Heatmiser doing an unreleased full-band version of his released solo song "Christian Brothers." Sam Coomes is playing bass on this one. The band recorded it during the sessions for Mic City Sons, but it was not mixed at that time because by then Elliott had decided to use his solo version on his second solo album. Tony Lash mixed this version after Larry Crane dug it up from the archives. I really love all the layers and waves of warm sound that it becomes.

5. "Hamburgers" (performed with Neil Gust), 1995

This unreleased track was recorded at the Heatmiser House temporary studio. Neil Gust of Heatmiser is on drums and Elliott is on keys. I love this one because you would never know it was Elliott or Neil. It sounds more like Money Mark and the Beastie Boys. Just a fun improv jam, I am sure, of which Neil had no recollection when I asked him.

6. "Plainclothes Man" (solo version), 1996

I included Elliott with Heatmiser doing a song that would be released solo instead ("Christian Brothers"), and I wanted to do the inverse too and include Elliott doing a solo version of one of my favorite Heatmiser songs. In the movie, we transition between both versions. I think this is another example of Elliott trying songs out in different ways to see which he liked better, solo and stripped down or more layered, bigger version with Heatmiser.

7. "Unknown Song" (instrumental), 1994

This song was recorded at Quasi House in Portland. Larry Crane recalled Janet Weiss telling him that Elliott would sometimes stay at her and Sam's house when they were out of town, and he would use Quasi's Fostex 8-track 1/4-inch reel-to-reel and mixer. This song was probably from one of those times.

8. "Say Yes" (live at Yo-Yo Festival), 1997

I remember the first time I heard this live performance and the audience banter at the beginning ("Play the one about the girl!") and I thought this would be a perfect way to set up and introduce Joanna [Bolme, Elliott's onetime girlfriend] in the film. It was one of the ideas that I offered that stuck and made it in the final edit, and I'm glad because it is such a very sweet part of the film about two very sweet people who were often very sweet to each other. It's also a good way to subtly talk about how much of an influence Joanna was on Elliott, and also the breakup that would come along with it. The line "I just wish it was delivered under better circumstances" speaks volumes without getting into the details.

9. "Unknown," (instrumental), 1994

This unreleased instrumental comes from the sessions for Elliott's second album, found on the same 1/2-inch, 8-track reel with "Needle in the Hay," "Alphabet Town," "Big Decision," "Whatever (Folk Song in C)," "Some (Rock) Song" and is listed simply as "Unknown."

10. "Coast To Coast" (early version), 1995-96

Another example of Elliott's recycling. This is a very early and unreleased version of "Coast to Coast" which would later be posthumously released on the album From a Basement on the Hill. This one starts off with similar lyrics to the released version. The lyrics are the same for about the first verse or so—he does change the "If you can't help it, then just leave it alone" to "If you can't help me, leave me alone," although he goes back to the "it" version later in the song when he comes back and repeats the first verse. But other than that first verse or so, the rest of the words are almost completely different from the two versions. He mentions "Mary," who appears in many other songs, and instead of "still you're keepin' me around," he sings "go home, go home."

11. "Waltz #1″ (demo), 1997

This is the demo version that was from Larry Crane's original DAT of the mix and was recorded at Jackpot! Studio here in Portland. Larry recalls that they originally labeled this demo "Bushmills," probably because of activities the night before. They only spent a few hours recording it, and then walked over to the bar and grill where Joanna's sister worked and had drinks.

12. "Untitled Soft Song in F," 1993

This another unreleased instrumental, and the song name "Untitled Soft Song in F" is actually Elliott's given title for this track. It's another on that cassette with "Carl's El Camino," "Last Call," "We're All Friends Now" and "Don't Call Me Billy," which we heard and talked about earlier.

13. "True Love," 2001

This was one of the songs that Elliott would often demo and play after hours at Largo when hanging out with friend and owner Mark Flanagan and musician Jon Brion. This was recorded around the time Elliott and Jon Brion went into a small studio to record the track, partially as an attempt to help him get to focus on non-drug activity. I've heard, I think, two or three different versions of this song, and the lyrics evolved and shifted from a love interest to a major drug interest instead.

14. "Miss Misery" (live on Late Night With Conan O'Brien), 1998

Everyone knows this song because its the one that got him the Academy Award nomination, where he performed it in the white suit. In the film, we probably did the opposite of what people expected by showing the Conan O'Brien performance instead of the Academy Awards. But we do show both in the film, we just hear this one and sit with it longer. This is Elliott's first TV appearance, 18 days before he would perform at the Academy Awards accompanied by the house orchestra.

15. "L.A.," 1999

This song is from Elliott's Figure 8 album and is used to illustrate Elliott's move to Los Angeles. It feels triumphant and energetic when the song kicks in with visuals of the car rolling into town with the palm trees and sun flying past the car windows of downtown L.A.

16. "Son of Sam" (acoustic), 1999

We included the alternate version here rather than the released version. Although the release sleeve on the single doesn't specify this as the acoustic version, it is much different from the Figure 8 release, and this version appears as a B-side on that album's first single, "Happiness." Elliott really only pick strums on this acoustic version, whereas he had an electric riff on the Figure 8 version. "Something's happening, don't speak too soon I told the boss off and made my move…"

17. "The Last Hour" (early version), 1999

This is an early unreleased version of the song that would later be released on the posthumous album From a Basement on the Hill. There was also a third version with all instrumentation performed on an organ that we considered to use here, too, but when put into the edit with all of the emotionally loaded interviews, the organ sound just seemed a bit too funeral-like and was too haunting for an already heartbreaking part of the movie. We didn't want to stomp too hard on hearts.

18. "Everything Means Nothing To Me," 1999

In the film we use a live performance with Jon Brion that we mixed into the studio version. Since we couldn't use half of each version like that on the soundtrack, I included the released version because it really is so beautiful. I remember that Elliott said it was one if his favorite songs at the time because it was idiosyncratic, which I would agree with and I remember him also saying that it might seem dreary to others but that the song is a very positive sentiment to him.

19. "Happiness," 1999

Another one of the very few songs to appear on the soundtrack that was already released, but for good reason, because it closes our film. It was also the last song to be performed as an encore with all friends onstage at the four charity shows that Elliott's sister put on in Portland, L.A., N.Y. and Dallas to celebrate what would have been his 44th birthday. Elliott once said that there has to be a certain amount of darkness in his songs for the happiness to matter. And to me this song feels like that sentiment put to music, because this song kind of has both, like his life had both, like all of our lives have, and he is talking about the dark but then asking for it to be put away in exchange for happiness instead.

20. "I Love My Room," 1985

This was recorded in spring of 1985 in Portland, recorded partly in the basement of Garrick Duckler's parent's house, during a time when Elliott was looking to get his own apartment. Garrick was a friend from high school who would write and record with Elliott under the moniker of Stranger Than Fiction and other names. We thought it might be from that, but Garrick says it isn't a Stranger Than Fiction song, so I think it is just a really young Elliott track. Because this song is so young, we used it early in the film and then also at the end of the movie during the credits, but I put it at the end of the album since it is so long and just kind of seemed out of place in terms of album flow amongst all the other more mature stuff.

I think also the intention is also to send the listener away with that aural sense of young innocence and purity, pointing back to how Elliott began and what he always was—someone's brother, someone's son, someone's childhood friend. And, if you listen to the very, very end, even after it seems like the song is over, you hear this haunting part of Elliott singing, "See you in a while my baby/See you under the willow tree," which then fades away. I think that last line makes for good final sentiment of goodbye from Elliott.

HEAR IT: Heaven Adores You (Original Motion Picture Soundtrack) is out Feb. 5.