(Fr. su je t; Ital., terna, soggetto ; Ger. Thema, Subjekt) is used generally to mean a phrase of melody, with or without harmony, of sufficient distinction to bo regarded as a musical thought. Every species of musical F orm (q.v.) is dependent for consistency on the use of subjects of one kind or another, and the history of musical form is largely concerned with the increasing clearness in articulating the subjects, from the rhythmless adoption of canti fermi by mediaeval composers to the incisive rhythmic figures of the classical era (see Canto F ermo and F ig u r e ). Tho whole of the fugal stylo of writing is generated by the recognition of one or more prevalent subjects as a starting-point. The immanence of the subject is as important to the free use of I mitation (q.v.) in the modern style as it was to the strict writers of F ugue (q.v.). Each form (see Sonata ; S ymp h o n y ; S u it e ) has had its own kinds of subjects suitable to its special method of development. c.