Hi Drew,
You're my favorite kind of skeptic.
The perceived character of the sound changes gradually with frequency. For pure tones the tonal character and the sensation of pitch decrease with decreasing frequency, and they both cease around 20 Hz. Below this frequency tones are perceived as discontinuous. From around 10 Hz and lower it is possible to follow and count the single cycles of the tone, and the perception changes into a sensation of pressure at the ears. At levels 20-25 dB above threshold it is possible to feel vibrations in various parts of the body, e.g. the lumbar, buttock, thigh and calf regions. A feeling of pressure may occur in the upper part of the chest and the throat region.
I wonder if your impressions were different than what they describe?
I thought that a pure 4hz tone didn't suggest very much chromatically. It wasn't music. But when the synthesized chords played you could sense that the "beating" if you will of the really slow frequency has a harmonic relationship to the higher tones. It also contributed a rhythmic component to the music that I imagine could either seem complimentary or clashing.
I think there's potential for creating music that seems musical.
I liked the effect best when the lowest tone was just at the threshold of hearing and not such a prominent beating tone. When it was just at the threshold it had a tremendous ability to accent a sense of emotion.
I think there's lots of potential for making fresh content but I wonder how many people will ever be able to listen.
best regards,
mike