Musicianship Tip: What "In a Key" Really Means

In the next unit of "Set Sail," you will learn songs that are all "in the key of C major."
In subsequent units, we will switch keys to the keys of F major, A minor and, finally, Gmajor.

So, first, what does it mean to "be in the key of" a particular note?

To answer this, I will simply use a number, a number which you will hear me say over and over again throughout all subsequent lessons and courses:

"One"

Please let me explain:

When you play a song whose melody only uses the seven natural notes, there forms around one of those notes (C) a magical center of gravity, a feeling that, once we reach that note C out of all the seven notes, that we are done or home.

We call this powerful note in a scale scale degree #1, or simply One. (We also refer to it as the root of the scale.)

This concept is difficult to explain in words, so please listen to the examples I'll play now.

I will noodle around the seven notes of C Major and then I'll clearly land on the root, or scale degree #1, or simply One, which in the Key of C Major is the note C.

Hopefully, when I land on the root or one and pause to look up at you, you too will feel a satisfying sense of being "done" or having reached "home."

Well, how was it? Could you hear the difference between the "tension" of floating around all of the notes versus the "relief" of finally getting "home" to one?

This feeling of being home is what one or root really means in western harmony. It is this feeling that lets our ears and bodies know what key the song is in.

Regardless of which major scale you are playing, it will alway contains the same seven letter notes in the same predictable order.

And one of those notes will always be this "center of gravity" which we call the one or the root of the key.

When all seven letters are natural (as you have learned them), the note C fills this role. C is the one or root of this all-natural scale.

And when we switch to a new scale by altering one of the seven natural notes, one of those other notes will always become the new center of gravity to your ears.

This note is what we call the one or the root of the key.
The note which is one is also the name of the major scale and the name of the key. For

example, all of the following statements are true:
The one or root of the C major scale is the note C.
When we play only the notes of the C major scale, we are playing in the key of C. When we are in the key of C, the one or root of that key is the note C.