We getting addicted so it keeps us from getting bored
C is what i always have so ima go with C.
The sensation of a frequency is commonly referred to as the pitch of a sound. A high pitch sound corresponds to a high frequency sound wave and a low pitch sound corresponds to a low frequency sound wave. ... That is, two sound waves sound good when played together if one sound has twice the frequency of the other.
Yah isnt that obvious? Gasses mix everywhere in all proportions.