Moonglow (song) - Musicological Notes

Musicological Notes

"Moonglow" is a 32-bar tune in the form of AABA.

"Moonglow" appears in jazz fake books and lead sheets in the key of G, though it is also thought to originally be in the key of C. It is tonal, however it begins on the IV chord, also referred to as the subdominant major chord, and the sixth, or submediant note of the major scale, before resolving onto the tonic.

The melodic riff of the A section is composed of a repeated minor third interval followed by a major third interval and then a repeated note. Harmonic movement is largely in an ascending circle of fourths, or with descending chromatic substitutions, but there is also movement between thirds or between major and minor seventh chords. Minor seventh chords are often played in first inversion in this tune, and may therefore be thought of and notated as six chords of the relative major.

Rhythmically "Moonglow" is in 4/4 time. It is a foxtrot typically played at a slow tempo, although some performers, notably Art Tatum, have played it faster. The rhythm is syncopated. Jazz players will usually swing the eighth notes.