Rules for 2nds:
- The intervals that are white notes use only white piano keys. Those that are black notes use at least one black piano key.
- A 2nd uses two letters in a row. Its “size” depends on how many keys we skip. For instance, E—F skips no keys. C—D skips one key. C—D# or Db—E skips two keys.
- A minor 2nd is also called a “half step”. It skip no keys.
- A Major 2nd is also called a “whole step”. It skips only one key.
- An augmented 2nd is whole step + a half step. It skips two keys.
Below is an illustration of 2nds in several scales.
Colors show the type of 2nds:
- All 8th notes colored black and beamed form Major 2nds. Major 2nds are also whole steps.
- All 8th notes colored red and beamed form minor 2nds. Minor 2nds are also half steps.
- In harmonic minor, the two 8th notes colored blue and beamed form an augmented 2nd. Augmented 2nds are a whole step + a half step.