Counting intervals

Key idea An interval is the distance between two notes. Count letter names including both ends: C up to E is C, D, E, a third.

The interval number depends only on letter names; ignore black keys for now. The same note twice is a unison (1), the next letter is a second, and so on up to the octave (8).

Seeing intervals on the staff

• Odd intervals (3, 5, 7): both notes are the same type, line-line or space-space.
• Even intervals (2, 4, 6, 8): one note on a line, the other in a space.
• Third: line to the next line. Fifth: line to line, skipping one line between.