Lydian

What it means

The Lydian mode runs on the natural notes from F to F. Compared with major it differs in a single note: the fourth degree lies a semitone higher, so that an augmented fourth stands above the tonic. This note gives the key its open, wide, floating and bright sound.

Musical use

In the order of the church modes, Lydian is the fifth mode; its plagal form is called Hypolydian. In traditional practice, however, the raised fourth degree was often lowered by musica ficta, because together with the tonic it forms the tritone, felt to be awkward. The mode thereby approached the later major scale, and the sources are inconsistent about this — in scholarly editions the decision is recognizable by small accidentals above the staff.

Outside early music, Lydian is extraordinarily alive. In the folk music of certain regions the raised fourth degree appears regularly; in jazz the Lydian scale belongs to the stock of chord-scale associations; and in film music the Lydian sound is a common means for expanse, height, and wonder — which has directly to do with the openness of the sound.

Lydian is to be distinguished from Ionian, which it resembles except for the fourth degree. This one note is the whole hallmark, and it wants to remain audible in playing.

In the medieval order, Lydian is the fifth church mode. Its augmented fourth above the finalis was often replaced in practice by a flat, so that the mode sounded like F major. In modal jazz improvisation, Lydian is the preferred scale over major seventh chords with a major seventh. In film music the raised fourth is used for floating, wondering effects.

Performance practice

Watch the fourth degree — it is the note that decides, and the ear tends to lower it involuntarily. Give Lydian passages time; their effect lies in floating, not in pressing forward. And practise the mode on the same tonic in comparison with major, so that the difference becomes ingrained.