Ex.1)12lineNumRule01 The interval ruler that makes up all Music Scale Formulas. We measure the distance between notes in half steps instead of inches like a ruler (Ex.1).

Ex.2)12lineIntRule01In a 12 note chromatic scale the 1-12 is intsead 1-7 and we have 5 between accidental numbers b2, b3, b5, b6, b7 none between 3&4, 7&1(Ex.2).

In music scale theory we use numbers for intervals as an easier way to measure the distance or steps between notes in a music scale and also notes in a music chord. If we count higher than 7 we go into the next octave and 1 starts over again as the 1 in the square of this chromatic scale (Ex.2a). This applies to music scale theory (In harmony chord theory we use numbers higher than 7 called compound intervals this will be explained in future lesson. Every music scale has a music scale formula (1, 2, 3, 4, 5, 6, 7 is the Major Scale Ex.4), (1, b3, 4, 5, b7 is the minor Pentatonic Scale Ex. 5) the bordered numbers. The notes in music are taken from the first 7 letters of the alphabet A-G with 5 accidentals that each have with 2 names (incrementing A to A# sharps & decrementing B to Bb flats A# and Bb are the same) C#-Db, D#-Eb, F#-Gb, G#-Ab. There is no accidental notes between B-C, and E-F (Ex.3). This can be a challenge to learn because we have to break away from our old mind associations of how we uses letters in the alphabet as well as number in counting. The diagrams below can give a better perspective to understand the interval ruler. You see dynamically how the bordered numbered notes below overlay the static letter notes to measure the distance between the notes. This creates easy to recognize scale shapes and is an aid for guitar players who play by ear.

Ex.2a)                                                Ex.3)                                             Ex.4)                                                 Ex.5)