Because I've been in Choir for 3 years now, I have a very good understanding of how pitch works. Pitch is "the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone the quality of a sound governed by the rate of vibrations producing it; the degree of highness or lowness of a tone." I really wouldn't know how else to word how pitch works, but I do understand it. I also understand how octaves work, which are closely related to pitch. Reading the treble clef was simple, but the bass clef took some time to learn.
PITCH CLASSES AND PITCHES
Each letter name reappears every eighth position: eight below C is another C. Notes that are eight letter names apart make an ocatave. They sound similar, a principle known as octave equivalence. Octave-related notes belong to the same pitch class and have the same letter name.
THE PIANO KEYBOARD
On the keyboard any key to the left of two black keys is pitch class C. To the left of any three black keys is pitch class F. Middle C is often used as a reference point, it is the C closest to the middle of the piano keyboard. The black key pitches are named in relation to white key pitches. Any black key immediately above/to the right of any white keys gets the white note's letter name plus a sharp (#). Any black keys to the left of a white key gets the same note name plus a flat. Every black key can have 2 names (sharp or flat), these notes are what is called enharmonic. The sharp and flat symbols are classified as accidentals. Another common accidental would be a natural. Here is a piano keyboard with the letter names: