Anti classical

of, relating to, or characteristic of greek and roman antiquity:
cl-ssical literature; cl-ssical languages.
conforming to ancient greek and roman models in literature or art, or to later systems modeled upon them.
marked by cl-ssicism:
cl-ssical simplicity.
music.

of, relating to, or const-tuting the formally and artistically more sophisticated and enduring types of music, as distinguished from popular and folk music and jazz. cl-ssical music includes symphonies, operas, sonatas, song cycles, and lieder.
of, pertaining to, characterized by, or adhering to the well-ordered, chiefly h-m-phonic musical style of the latter half of the 18th and the early 19th centuries:
haydn and mozart are cl-ssical composers.

architecture.

noting or pertaining to the architecture of ancient greece and rome, especially the religious and public architecture, characterized by the employment of orders.
compare (def 27b).
noting or pertaining to any of several styles of architecture closely imitating the architecture of ancient greece or rome; neocl-ssic.
noting or pertaining to architectural details or motifs adapted from ancient greek or roman models.
(of an architectural design) simple, reposeful, well-proportioned, or symmetrical in a manner suggesting the architecture of ancient greece and rome.

(often initial capital letter) pertaining to or designating the style of fine arts, especially painting and sculpture, developed in greece during the 5th and 4th centuries b.c., chiefly characterized by balanced composition, the separation of figures from an architectural background, and the naturalistic rendering of anatomical details, spatial movement, and distribution of weight in a figure.
compare (def 4), (def 5).
of or relating to a style of literature and art characterized by conformity to established treatments, taste, or critical standards, and by attention to form with the general effect of regularity, simplicity, balance, proportion, and controlled emotion (contrasted with ).
pertaining to or versed in the ancient cl-ssics:
a cl-ssical scholar.
relating to or teaching academic branches of knowledge, as the humanities, general sciences, etc., as distinguished from technical subjects.
(of a given field of knowledge) accepted as standard and authoritative, as distinguished from novel or experimental:
cl-ssical physics.
(defs 1–5, 8, 10).
ecclesiastical. pertaining to a cl-ssis.
cl-ssical music:
a jazz pianist who studied cl-ssical for years.
adjective
of, relating to, or characteristic of the ancient greeks and romans or their civilization, esp in the period of their ascendancy
designating, following, or influenced by the art or culture of ancient greece or rome: cl-ssical architecture
(music)

of, relating to, or denoting any music or its period of composition marked by stability of form, intellectualism, and restraint compare romantic (sense 5)
accepted as a standard: the cl-ssical suite
denoting serious art music in general compare pop1 (sense 2)

(music) of or relating to a style of music composed, esp at vienna, during the late 18th and early 19th centuries. this period is marked by the establishment, esp by haydn and mozart, of sonata form
denoting or relating to a style in any of the arts characterized by emotional restraint and conservatism: a cl-ssical style of painting see cl-ssicism (sense 1)
well versed in the art and literature of ancient greece and rome
(of an education) based on the humanities and the study of latin and greek
(physics)

not involving the quantum theory or the theory of relativity: cl-ssical mechanics
obeying the laws of newtonian mechanics or 19th-century physics: a cl-ssical gas

another word for cl-ssic (sense 2), cl-ssic (sense 4)
(of a logical or mathematical system) according with the law of excluded middle, so that every statement is known to be either true or false even if it is not known which
adj.

1590s, “of the highest rank” (originally in literature), from cl-ssic + -al (1). cl-ssical music (1836) was defined originally against romantic music.

[i]n general, as now used, the term cl-ssical includes the composers active in instrumental music from somewhere about 1700 to say 1830. hence the list includes among the great names those of bach, his sons, haydn, mozart, beethoven, clementi, dussek, pleyel, cramer, etc. the next step beyond the term cl-ssical is “modern romantic,” the composers of which school may be taken to include all the writers for pianoforte from about 1829 (when mendelssohn published the first “songs without words”) down to the present. the term romantic in this sense means strongly marked, extraordinary, intending to tell stories and the like. [“music, its ideals and methods,” w.s.b. mathews, 1897]

but already by 1880s it was acknowledged the term had a double sense: music that had withstood the test of time, as well as music of a style contrasted to “romantic.” later (early 20c.) it was contrasted to jazz (in this sense more often with reference to the orchestras than to the music itself). still later in contrast to popular music generally (mid-20c.).