Something i really want to make, and see other people make are Solfeggio frequency mixes.
This is a great example that i love!
With all the Solfeggio tracks that are available, its possible to make quite a library of frequencies.
Ideal situation would be to take a sample of each tone and attach that tone to a key on a keyboard.
I would love to hear what people could do, i wish i could have ago but i don't have the software or the know how.