Hi Folks,
I do not wish to solicit a flame war, but have to say that music materials do readily go down to the 20Hz realm. And they do without any syth or electronic sources. The base tone for the lowest key of a piano is 27.5Hz (4 octaves down from the 440Hz "A"). A large organ will go at least 1/2 to full 1 octave further down. And this is so far considering "tonal" instruments only. Enter the purcussion; a large bass drum or gong will readily produce sound components down to well below human audible limits.
Cheers!
