When I want to listen to decent to good Microtonal and Lowercase I usually turn to 12k/Line artists
http://www.12k.com/ Pjusk is very good, especially the "Sval" CD. Longform "drone noise" and restrained sound exploration. Modified field recordings stretched out to form ambient passages.
0/R - "Varied" is true Lowercase; the very delicate sound of manipulated sine waves and background clicks and beeps pulsating into almost a rhythm of short burst noise.
Sébastien Roux - "Songs" is more of a free-improv, sound collage of noises and Electroacoustic samples, a few notes from Guitars, Pianos and Harps here and there spliced up and peppered minimally through the tracks, each song title showing which instruments were used i.e. "The Cello Song" or "The Harp and Contrabass Song". Two of my favorites of the 12k collection: the first is
Kenneth Kirschner - "Filaments & Voids" four tracks spread over 2 CD's and 100% atmosphere. Silence is utilized heavily and perfectly through-out as the label notes state
" Kenneth Kirschner focuses the listener's attention on the silence inherent in his sounds, and the sounds implicit in silence." The second is
Simon Scott who released his first LP last year, titled
"Below Sea Level". Blankets of smooth drones while the main backbone of the project, an electric Guitar, lazily picks away clean notes, string clicking, tapping, scraping in the most organic and non-electronic sounding way you can imagine a electronic artist being able to pull off. Awesome packaging as well: