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.