Numbering an interval

The tonic

The first note of a scale is its tonic. It gives the scale its name. So the tonic of G major is G, and the tonic of F major is F.

Count the letters

An interval is the distance between two notes. Its number comes from counting the letter names, counting both notes. Climb like a ladder: the lower note is 1, and each letter up is the next rung. C up to E is C, D, E: three letters, so a 3rd.

From a 2nd to an octave

Grade 1 intervals go from a 2nd up to an 8th. The 8th is called an octave: the same letter, eight notes up. On the stave, a line to the next line up is a 3rd. A line to the next space up is a 2nd.

Remember

• The tonic is the first note of a scale.
• Count the letters, both notes included.
• An octave is an 8th: the same letter again.