MUSIC THEORY

Interval Focus: Thirds

Compare minor and major thirds from the same root.

Count three letters

C, D, E make three letter names, so both C–E♭ and C–E are thirds. An accidental does not change the interval number.

Three or four semitones

A minor third (m3) is three semitones; a major third (M3) is four. Their target keys are adjacent when the root is fixed. This holds after transposition to another root.

Practice the relationship

Name m3 and M3 from keyboard pairs, then find the appropriate target key from each name.

See the notes behind every chord.

Explore piano keys and guitar frets, hear how chord progressions move, and bring music theory into your playing with Genchord.

Apple and the Apple logo are trademarks of Apple Inc., registered in the U.S. and other countries and regions. App Store is a service mark of Apple Inc.