A major scale is a group of eight notes that produces the familiar sound:
You now know all of the notes needed to play the C major scale.
The number underneath each note indicates its position in the scale. These numbers are called scale degrees. The distance from the first to the eighth note of a major scale is one octave. An octave is the distance between a note and its next repeat either higher or lower. The names of the first and last notes of a major scale are always the same.