BJ Nilsen’s “The Invisible City” is a tight, tight album, which seems to be an odd thing to say about a drone record. Usually drones are expansive and looping, circular and swaying, and at first I wanted more of that from this. The first track, “Gravity Station,” starts off quietly, stealthily, and slowly grows until it reaches its bursting almost 17-minute long conclusion. Near the end of the piece the tight drones are cut up with shards and other slashing, spinning sounds. That’s expansive enough for me, even though the circles it spins are still small.

A definite highlight on the record is “Scientia,” which starts with a vibrant high-pitched squeal. Nilsen lists all the field recordings he used on this, as well as the manipulations he performs on them, so those squeals could be anything from birdsong to wingflaps to birds eating. There’s also some door slamming, voice decoding, virtual Hammond and sine waves. It’s pretty cool to see all the field recordings listened, because they are definitely manipulated enough to be separated and unidentifiable from their sources. A second highlight is “Into Its Coloured Rays,” the track which sounds the most different from any track on the record. It has some really nice tones, sort of like the end of Alvin Lucier’s “I Am Sitting in a Room,” where everything is totally disintegrated and just these beautiful rainbow tones emerge. Finally, “The Invisible City,” the title track and last song, is a lush, sweeping piece that nearly explodes the end of the record after mostly quiet pieces. This is an intriguing album, put together quite nicely, although the pieces could use a little more variation. 6/10 -- Shannon Smith (19 May, 2010)