The previous discussion shows that the difference between popular and serious music can be grasped in more precise terms than those referring to musical levels such as "lowbrow and highbrow," "simple and complex," "naive and sophisticated." For example, the difference between the spheres cannot be adequately expressed in terms of complexity and simplicity. All works of the earlier Viennese classicism are, without exception, rhythmically simpler than stock arrangements of jazz. Melodically, the wide intervals of a good many hits such as "Deep Purple" or "Sunrise Serenade" are more diffficult to follow per se than most melodies of, for example, Haydn, which consist mainly of circumscriptions of tonic triads and second steps. Harmonically, the supply of chords of the so-called classics is invariably more limited than that of any current Tin Pan Alley composer who draws from Debussy, Ravel, and even later sources. Standardization and non standardization are the key contrasting terms for the difference.
 Structural Standardization Aims at Standard Reactions. Listening to popular music is manipulated not only by its promoters but, as it were by the inherent nature of this music itself, into a system of response mechanisms wholly antagonistic to the ideal of individuality in a free, liberal society. This has nothing to do with simplicity and complexity. In serious music, each musical element, even the simplest one, is "itself," and the more highly organized the work is, the less possibility there is of substitution among the details. In hit music, however, the structure underlying the piece is abstract, existing independent of the specific course of the music. This is basic to the illusion that certain complex harmonies are more easily understandable in popular music than the same harmonies in serious music. For the complicated in popular music never functions as "itself" but only as a disguise or embellishment behind which the scheme can always be perceived. In jazz the amateur listener is capable of replacing complicated rhythmical or harmonic formulas by the schematic ones which they represent and which they still suggest, however adventurous they appear. The ear deals with the diffficulties of hit music by achieving slight substitutions derived from the knowledge of the patterns. The listener, when faced with the complicated, actually hears only the simple which it represents and perceives the complicated only as a parodistic distortion of the simple.
 No such mechanical substitution by stereotyped patterns is possible in serious music. Here even the simplest event necessitates an effort to grasp it immediately instead of summarizing it vaguely according to institutionalized prescriptions capable of producing only institutionalized effects. Otherwise the music is not "understood." Popular music, however, is composed In such a way that the process of translation of the unique into the norm is already planned and, to a certain extent, achieved within the composition itself.
 The composition hears for the listener. This is how popular music divests the listener of his spontaneity and promotes conditioned reflexes. Not only does it not require his effort to follow its concrete stream; it actually gives him models under which anything concrete still remaining may be subsumed. The schematic buildup dictates the way in which he must listen while, at the same time, it makes any effort in listening unnecessary. Popular music is "pre- digested" in a way strongly resembling the fad of "digests" of prmted Material. It is this structure of contemporary popular music which in the last analysis, accounts for those changes of listening habits which we shall later discuss.
 So far standardization of popular music has been considered in structural terms--that is, as an inherent quality without explicit reference to the process of production or to the underlying causes for standardization. Though all industrial mass production necessarily eventuates in standardization, the production of popular music can be called "industrial" only in its promotion and distribution, whereas the act of producing a song-hit still remains in a handicraft stage. The production of popular music is highly centralized in its economic organization, but still "individualistic" in its social mode of production. The division of labor among the composer, harmonizer, and arranger is not industrial but rather pretends industrialization, in order to look more up-to-date, whereas it has actually adapted industrial methods for the technique of its promotion. It would not increase the costs of production if the various composers of hit tunes did not follow certain standard patterns. Therefore, we must look for other reasons for structural standardization--very different reasons from those which account for the standardization of motor cars and breakfast foods.
 Imitation offers a lead for coming to grips with the basic reasons for it. The musical standards of popular music were originally developed by a competitive process. As one particular song scored a great success, hundreds of others sprang up imitating the successful one. The most successful hits types, and "ratios" between elements were imitated, and the process culminated in the crystallization of standards. Under centralized conditions such as exist today these standards have become "frozen."  That is, they have been taken over by cartelized agencies, the final results of a competitive process, and rigidly enforced upon material to be promoted. Noncompliance with the rules of the game became the basis for exclusion. The original patterns that are now standardized evolved in a more or less competitve way. Large-scale economic concentration institutionalized the standardization, and made it imperative. As a result, innovations by rugged individualists have been outlawed. The standard patterns have become invested with the immunity of bigness--"the King can do no wrong." This also accounts for revivals in popular music. They do not have the outworn character of standardized products manufactured after a given pattern. The breath of free competition is still alive within them. On the other hand, the famous old hits which are revived set the patterns which have become standardized. They are the golden age of the game rules.
 This "freezing" of standards is socially enforced upon the agencies themselves. Popular music must simultaneously meet two demands. One is for stimuli that provoke the listener's attention. The other is for the material to fall within the category of what the musically untrained listener would call "natural" music: that is, the sum total of all the conventions and material formulas in music to which he is accustomed and which he regards as the inherent, simple language of music itself, no matter how late the development might be which produced this natural language. This natural language for the American listener stems from his earliest musical experiences, the nursery rhymes, the hymns he sings in Sunday school, the little tunes he whistles on his way home from school. All these are vastly more important in the formation of musical language than his ability to distinguish the beginning of Brahms's Third Symphony from that of his Second. Of ficial musical culture is, to a large extent, a mere superstructure of this underlying musical language, namely, the major and minor tonalities and all the tonal relationships they imply. But these tonal relationships of the primitive musical language set barriers to whatever does not conform to them. Extravagances are tolerated only insofar as they can be recast into this so-called natural language.
 In terms of consumer demand, the standardization of popular music is only the expression of this dual desideratum imposed upon it by the musical frame of mind of the public--that it be "stimulatory" by deviating in some way from the established "natural," and that it maintain the supremacy of the natural against such deviations. The attitude of the audiences toward the natural language is reinforced by standardized production, which institutionalizes desiderata which originally might have come from the public.