What about Modes?

The mode of song affects its mood and character.
Mode 1 is the ubiquitous major scale.
The other modes are simply offsets of Mode 1.

Mode 1
[1] [2] [3] [4] [5] [6] [7] [1]

Mode 2
[2] [3] [4] [5] [6] [7] [1] [2]

Mode 3
[3] [4] [5] [6] [7] [1] [1] [2]

Mode 4
[4] [5] [6] [7] [1] [1] [2] [3]

Mode 5
[5] [6] [7] [1] [1] [2] [3] [4]

Mode 6
[6] [7] [1] [1] [2] [3] [4] [5]

Mode 7
[7] [1] [1] [2] [3] [4] [5] [6]

Notice a pattern here?

Learn how to play Mode 1 and Mode 6 on your instrument.

A song centered around a [1], [4] or [5] is in a major mode. A song centered around a [2], [3] or [6] is in a minor mode.

-+=