When we sing a tone, we do not “create” anything, but simply borrow from the cosmos a tone, or vibration, that the Creator has placed there for our enjoyment. We integrate the vibration and “channel” it. Similarly, when we sing a melody, the various notes we sing in sequence follow a proportionality of the cosmos that musicians (and mathematicians) have discovered and used over the centuries (read more on this in Chant, traditional music of the spheres )
As quick illustration, below is a video of a tuning fork giving the tone of a 440 Hertz frequency*. In other words, this tuning fork vibrates 440 times per second. Conventions have named this note “A4”, or “A above middle C”). The note represented by twice the frequency (880 Hertz) is called the OCTAVE of A4, called by convention “A5”. The note represented by half the frequency (220 Hertz) is also the OCTAVE of A4, called “A3”. Listen to the difference between 220hz, 440 hz and 880hz here.
*NOTE: In our section where we detail the “Psalm Modes”used in “Introit and Communion verses”, we use this 220 hertz frequency (one octave down from 440 hertz) as “reciting tone”