Tape is one of those ambient-leaning groups who have released a lot of music, and while they have certainly progressed since they started, the gradations are slight enough that a newcomer to the group might have a hard time distinguishing between different releases. Having said that, Luminarium introduces what might be some of the more dramatic wrinkles into the trios sound, especially arriving on the heels of what might have been their most austere release in Rideau.

The playing of brothers Andreas and Johan Berthling and Tomas Hallonsten is still sparse, with timely notes and soft shifts ruling the day, but the trio has rarely been this concise. One could even argue that the group has never created songs that veered so close to pop-oriented sounds, but that might be pushing it just a bit. With ten songs running just over forty minutes, they certainly do pack more ideas into their shorter songs, though. "Beams" opens the release in familiar territory, with downright wearing guitar melodies weaving through nocturnal droning sounds and some quiet snare and cymbal hits. "Moth Wings" keeps things in a similar realm, with acoustic guitar playing off rich double-bass notes and almost insect-chatter electronics before the track shifts about halfway through and introduces some warm piano notes and soft electronic tones.

Both the artwork and song titles of Luminarium are tied somewhat to primitive spelunking, and these little barely-lit pieces fit the mood perfectly. "Mystery Mutiny" weaves spindly, filtered guitar notes and multiple synth layers into an eerie parlor track, while "Altamira" peeks out of the darkness slightly with a bright and hopeful ending that rides on a cheery cloud quite unlike anything the group has ever done. Because of the evolution to shorter songs, the group relies on prominent melodies more on Luminarium, and the resulting songs are somewhat hit or miss in terms of their effectiveness. It's a release that sounds great at all times, but even when the group stretches out to almost six minutes (as they do on "Parade"), their strengths become even more apparent. Not quite their best work, it's still pretty darn good.