With its pitch-perfect mix of drones, musique-concrete techniques, and American pop elements, as well as its skewed but beautiful tonality, Upgrade and Afterlife is certainly my favorite Gastr Del Sol album - and also one of my favorite albums of all time. The only things that even remotely resemble this album are the albums of the long-lived Colorado abstract band Biota and maybe some of the second Set Fire to Flames album. This is one you can come back to an infinite number of times and always discover something new to appreciate. Every element of this album, from its track sequencing to the rich, full production and sound, bespeaks a team of musicians firing on all cylinders and creating a clear-eyed document of their collaboration. As much as I enjoy both O'Rourke's and Grubbs' subsequent solo work (and I tend to enjoy O'Rourke's a bit more), an earlier reviewer here was right - there was something special in their collaboration as Gastr Del Sol that is missing in their individual later works.Among the most ear-pleasing aspects of this album (that is less prominent on Camofleur) are the haunting, ethereal tape effects and production-work that flit around the corners of the music like restless ghosts. For example, in the track The Sea Incertain, Grubbs' strange (yet beautiful, almost Morton Feldman-like) piano is full-bodied and rich for several measures, and then is abruptly sliced by static - it's still present, only now it sounds like you're hearing it through hundreds of miles of long-distance land line telephone transmission. Later in the song, Grubbs' full piano sound returns, but warbly, degraded loops of the very chords he is playing are now hovering in the audio field, panning left to right. It's precisely these little moments of sonic confection that are all over the album that demonstrate how much care and creativity was put into this recording.Although the songs (the melodies, the chords, the lyrics) themselves are good, to me the most exciting thing about this album (and again, which elevates it over Camofleur in my opinion) is the way that the songs proper are refracted and skewed by these production techniques and embellishments - it feels like you're dreaming the album as you're hearing it, or listening to someone's hazy, half-remembered recollection of a great album from their youth.The bookends of the album deservedly get a lot of attention - the opener is a beautiful piece of musique concrete, the way the organ drones are emotionally ambiguous, the way out-of-context noises and sounds appear in the mix and suddenly change the whole makeup of the piece, the out-of-nowhere film music sample. Unlike a lot of American "post-rock" from this era that seemed to conflate nicking from outre genres with artistic quality, this piece has a narrative unfolding, a clear, linear process of going from one sonic point to another. This coherence and sense of narrative is extremely hard to do with abstract pieces like this. The closer functions similarly - at first it is a very faithful Fahey reconstruction, but then the tonality shifts, it becomes dustier, drier, a bit uneasy, until finally the whole thing is swallowed by Conrad's violin drone swells.But as much as I enjoy the opener and closer of the album, it's really the songs in the middle that make it for me. My personal favorite track is The Relay. But all the songs in the middle are great: Grubbs' piano chords are just so thick and full, with strange but beguiling harmonies; the lyrics are bizarre, maybe even non-sensical but they still carry a deeper, more intuitive meaning than simple word salad would; the arrangements are strange and spare and the tape effects/noises actually suit the songs rather than dress up deficient songwriting (as is so often the case in lesser albums of this type).I enjoy their other albums, especially Mirror Repair and Camofleur, but this has been a favorite of mine for close to two decades now and I don't imagine my enjoyment of it will fade.