The music produced, however, bore no longer a specific relationship to jazz, which latter continued to develop along the lines normal to any product that has become an article of mass consumption, a variable product excluding neither imagination nor musical talent, but always remaining a _genre_ and, by reason of its inherent restriction, never becoming a style. The features which once attracted attention by now had been absorbed into the contemporary musical vocabulary to which jazz could make no further contributions. Jazz, on the other hand, takes the materials of contemporary music, adopts those of its technical methods it can absorb and transforms them for its own uses. Infinitely more than even in the case of “serious” music, the composition and performance of popular music are controlled by commercial interests representing millions of dollars; in the economy of music business this fact constitutes a chapter in itself. The “serious” composers during the thirties were attracted by the two tendencies which years before had dominated the European musical scene: the _neoclassic_ tendency, and that which is roughly summarized as _Gebrauchsmusik_, literally _utility music_. In Europe, these tendencies were closely allied since one term implies an aesthetic, the other a practical purpose, and since they have the impulse toward new simplicity and a new relationship with the public as a common basis. As a result, _neoclassicism_, aiming at a clear and accessible profile and derived from more or less self-conscious evocations of music of the past, efficiently served as an idiomatic medium appropriate to the purposes of utility music. In the United States, explicit “returns” to this or that style or composer were few, and the neoclassic tendency was by no means always connected with a drive toward better relations with the public. Widely adopted, however, was a radical _diatonicism_, in the last analysis derived from the _neoclassic_ phase of Stravinsky and adapted to utilitarian ends (as in music for film or ballet by Aaron Copland or Virgil Thomson), to fantastic and parodistic purposes (as in the opera _Four Saints in Three Acts_ of Virgil Thomson and Gertrude Stein), or to “absolute” music as in certain sonatas and symphonies of Aaron Copland. The name Copland is always present when one speaks of the differing tendencies within the development of the past forty years. A large share of the various phases through which our music has passed during these decades is summed up in his work. He not only passed through them himself, but guided many young composers as friend and mentor. Notwithstanding his manifold transformations--and it is altogether possible that there are more to come--he has remained a strong and well-defined personality, easily recognizable in the differing profiles his music has assumed. * * * * *