Overview
"Pulstar" (possibly a portmanteau of "pulsar" and "star") was to be the most popular track, building on a synthesizer pulse sequence, a main line and various other synthesizer brass lines. It ends with a recording of the speaking clock.
"Freefall" builds on a gamelan sequence and a synthesizer line.
"Mare Tranquillitatis" is a quiet synthesizer piece featuring recordings of several Apollo moon landings. Samples of this track can be heard on Enigma's album, The Cross of Changes (uncredited).
"Main sequence" is propelled by a pulsed synthesizer sequence, along which drums-based jazz track develops. It calms down and flows into—
"Sword of Orion", built on an arpeggio chord, melody, and percussion.
On "Alpha", Vangelis employs a composing technique he would use extensively on later albums (e.g. Direct): a simple theme of a few bars is developed through increasingly complex instrumentation. Instruments include a slow synthesizer arpeggio, synthesizer mallet melody line, xylophone, percussion and (later) acoustic drums. It is a rather upbeat piece.
The "Nucleogenesis" suite is a collage that conveys a somewhat darker mood, employing a church organ, an organ synthesizer pulse, various lines of Vangelis' patent synthesizer brass, acoustic drums and basses. Although hard to classify, the pieces appear to hold a ground between classical, fusion and progressive rock.
The title track, "Albedo 0.39" is an atmospheric track building on waxing and waning synthesizer chords and arpeggios, while a voice, reputedly the album's engineer Keith Spencer-Allen, narrates various physical properties of the Earth, such as its mass, length of the year in various measurements, and, finally, its albedo.
Read more about this topic: Albedo 0.39