The tuba is the outcast of the brass family. Big, fat, clumsy, and physically difficult to play, it discourages experimentation. There are a few tuba players in avant-garde music: Joe Daley, Mark Weaver, Leo Bachmann, and Oren Marshall. None of them have gone as far as Tom Heasley to transform the sound of the instrument. On his second album, On the Sensations of Tone, he uses electronics to create beautiful ethereal soundscapes. The low register of the tuba produces deep drones akin to (but not quite like) a didjeridoo. When digitally sustained, notes in the high register masquerade as ambient synthesizer sounds. The CD is comprised of two pieces. The 14-minute "Prelude" was recorded by Robert Rich, a logical partner in this adventure. If it weren't for the main sound source, the music of Heasley and Rich would have a lot in common. "Thonis" (42 minutes) was recorded live during a radio broadcast. Both are unedited improvisations. Comparisons to Robert Fripp and Brian Eno are inevitable, especially since the tuba's presence dissolves from within the soundscape. The second piece becomes a bit overlong and in the end the listener gets the impression that there is not much more to squeeze out of this concept, but it sure makes a soothing CD.