What Are Keys?
We do not use all 12 notes in every song. Generally, smaller groups of 7 notes can be taken out from the entire set of 12 notes to form a key. The key of the song is therefore the set of notes you use in the song.
One example is all the 7 white notes, which we call “C major”:The notes of a C major key are: C D E F G A B
The notes are chosen based on certain fixed intervals between them. We first write all the notes:
C C# D D# E F F# G G# A A# B C...
Starting with C, we (refer to the above keyboard:
i) Move up by two notes --> D
ii) Move up by two notes --> E
iii) Move up by one note --> F
iv) Move up by two notes --> G
v) Move up by two notes --> A
vi) Move up by two notes --> B
vii) Move up by one note --> C, and the cycle repeats.
Therefore, to obtain the scale, we start with the first note, and then move by 2, 2, 1, 2, 2, 2, and lastly 1 note.
Try to obtain the D Major scale. Did you obtain D E F# G A B C# D?
Try it out with every single note, and write it down in a table. Leave a comment if you're unsure .