The Note C

The white piano key to the left of each group of two black keys is the note C, so there are many C notes on the piano. However, each one of those C notes is a different pitch. Pitch refers to how low or high a note sounds. Note simply refers to the letter name.

Here are all the C’s played one after the other. They are all the same note (C), but different pitches (lower and higher).

Piano keyboard showing all C keys.


How can a letter name like C be a label for multiple pitches? How can there be different C’s? Science. Sound is produced from vibration. If a plucked string vibrates 262 times per second, it produces the pitch we label as C. You can use shorthand for “times per second” using the scientific measurement Hertz (Hz). Vibrating at 262 times per second is written as 262 Hz. If a string vibrates at double that rate (524 Hz), it’s the next higher C. If it vibrates at half (131 Hz), it’s the next lower C. A letter name indicates the same family of pitch. For a pitch to be labeled as C, its vibration must be a multiple of 262.

If you dive deeply in to the physics of sound, you’ll discover that the pitch C doesn’t always vibrate exactly at multiples of 262. It varies slightly based on several factors. Still, a letter name simply indicates a family of pitches vibrating in multiples.

You may have heard of A440. That refers to the note A just to the right of the center of a piano keyboard which vibrates at 440 Hz. You can probably guess that the next two lower A’s would vibrate at 220 Hz and 110 Hz and the two next higher A’s would vibrate at 880 Hz and 1760 Hz.

Each letter in the musical alphabet represents a family of pitches vibrating in multiples of each other.

One Pattern Block

Since the piano keyboard repeats the same pattern of keys over and over, we can focus on just one block of the pattern. Let’s add the rest of the natural notes. Remember – the white keys are the natural notes. It’s common when studying the piano keyboard to start on the note C. The following pattern starts on C and continues through all the natural notes (which begins the next pattern).

Piano keyboard with one octave highlighted.

What about the guitar? Don’t worry! We’ll get there. But we need a bit more information about notes in general first. Hopefully you’re starting to see how notes relate to each other when laid out horizontally, as on a piano keyboard (and guitar string).

Check Yourself

Answer the following questions.