Major and Minor Scales
Music is patterns of sound, and two fundamentals in music are rhythm patterns (how combinations of long and short notes relate to a steady beat or pulse) and pitch patterns (what notes are played).
The specific pitches used in a piece of music are usually derived from a scale. This post explores major and minor scales for piano and guitar.
The Circle of Fifths
The circle of fifths is a way of organizing the keys so that their patterns become apparent by arranging the 12 keys like the 12 positions on a clock, with each position being a fifth away from the keys on either side.