tetrachord
/ˈtɛtrəˌkɔrd/
noun
- A series of four musical notes that form the basis of a scale in ancient Greek music theory.
- The teacher explained that a major scale is made of two tetrachords joined by a whole step.
- The ancient Greek tetrachord consisted of four notes spanning a perfect fourth.
- Music students learn how a tetrachord can be combined to form a full scale.