Shhhh. Wired has an interesting article about music at its most subtle. Whisper the Songs of Silence.
“Lowercase sound” is the name given to a loose movement in electronic music that emphasizes very quiet sounds and the long, empty silences between them. Created largely by scientists, techies and experimental musicians, lowercase recordings are frequently based on the magnification of minute sounds through a computer, typically a Macintosh.
Recent compositions include a bubbling symphony of boiling tea kettles, the gentle hiss of blank tapes being played through a stereo and the soft bumps of helium balloons hitting the ceiling. One recent album was so quiet, listeners wondered whether it actually contained any sound at all.