Note 1 — I INTRODUCTION ROMANTICISM IN MUSIC
Reading edition
Properly speaking, "form" refers to the molecular constitution of music, to the ways in which relations of pitch and rhythm are manipulated in melody and harmony; "structure" to the molar constitution of music, the subsequent grouping of the melodies into complete pieces. The difference between a sonata, a fugue, and a nocturne is a difference of structure; the difference between a good melody and a bad one is a difference of form.