Lydian and mixolydian
Audio: lydian and mixolydian (0:08)
lydian and mixolydian plays a lydian melody on the trombone followed by a mixolydian melody on the French horn. The lydian and mixolydian figure shows the score:
- Bar 1 is an ascending scale in the key of F lydian.
- Bar 2 is a melody using the first four notes of the lydian mode.
- Bar 3 is an ascending scale in the key of G mixolydian.
- Bar 4 is a melody using five notes of the mixolydian mode.
The lydian mode contains the sequence of whole tones and semitones: TTTSTTS.
F lydian contains the notes FGABCDE.
A tritone is present in all the modes, including the major scale. The position of the tritone in a modal scale is one of the features that distinguishes one mode from another. In the lydian mode, the tritone, TTT, is between the tonic and the fourth degree. In the key of F lydian this tritone is the interval FB. The last three notes of the melody in the second bar of lydian and mixolydian move from F to B to F again to emphasise the tritone.
The mixolydian mode contains the sequence of whole tones and semitones: TTSTTST.
G mixolydian contains the notes GABCDEF.
It is the interval of a minor seventh above the tonic that gives the mixolydian mode its unique character. This feature distinguishes it from the major scale which has a major seventh above the tonic. In the key of G mixolydian the minor seventh is the interval GF. The last two notes of the melody in the fourth bar of lydian and mixolydian move from F to G to demonstrate the sound of a minor seventh.