The sounds below 21kHz can be very delightful. Of course they must be under that value of Hz in order we (humans) can hear them.
In guitar some sounds based on the mixolydian, dorian and/or minor can drive us into some distant places where only our mind can travel.
Take a listen to prana, feel the energy and see what I mean.
And if we use the lydian dominant among that it will be more dense and colorful.
Some words about me:
I became interested in guitar at the age of thirteen after a camping weekend. Back at home I had motivation to learn it. Listening to Jimi Hendrix learned the pentatonic and a few diatonic scales. Great gurus of guitar opened my mind with other ways of playing with their wonderful music.
The joy of playing a 23-year-old acoustic guitar was very noticeable.
When I had my first electric guitar I developed new techniques and wanted to have a better knowledge about modes of the major, minor, harmonic minor and melodic minor scales among other non-diatonic scales.
I always appreciated blues, metal and classical compositions.
Back in ’98 I started recording some tunes and now I decided to open the door this way to my musical world.
I also play guitar with Hematoma since 2001. Take a look at hematoma.pt.vu