In music theory and music criticism, the term eclecticism refers to the use of diverse music genres. A musician might be described as eclectic if different parts of their output can be ascribed to different genres such as folk, rock, electronic, classical, or jazz.
Eclectic musicians may also use historical references in their work. A song can reference historical forms and methods through its composition, arrangement, or production.
Progressive music is music that attempts to expand existing stylistic boundaries associated with specific genres of music. The word comes from the basic concept of "progress", which refers to advancements through accumulation, and is often deployed in the context of distinct genres, with progressive rock being the most notable example. Music that is deemed "progressive" usually synthesizes influences from various cultural domains, such as European art music, Celtic folk, West Indian, or African. It is rooted in the idea of a cultural alternative, and may also be associated with auteur-stars and concept albums, considered traditional structures of the music industry.
As an art theory, the progressive approach falls between formalism and eclecticism. "Formalism" refers to a preoccupation with established external compositional systems, structural unity, and the autonomy of individual art works. Like formalism, "eclecticism" connotes a predilection toward style synthesis or integration. However, contrary to formalist tendencies, eclecticism foregrounds discontinuities between historical and contemporary styles and electronic media, sometimes referring simultaneously to vastly different musical genres, idioms, and cultural codes. In marketing, "progressive" is used to distinguish a product from "commercial" pop music.
Eclecticism is a kind of mixed style in the fine arts: "the borrowing of a variety of styles from different sources and combining them" (Hume 1998, 5). Significantly, Eclecticism hardly ever constituted a specific style in art: it is characterized by the fact that it was not a particular style. In general, the term describes the combination in a single work of a variety of influences—mainly of elements from different historical styles in architecture, painting, and the graphic and decorative arts. In music the term used may be either eclecticism or polystylism.
Progressive rock (shortened to prog rock or simply prog) is a broad genre of rock music that primarily developed in the United Kingdom through the mid- to late 1960s, peaking in the early to mid-1970s. Initially termed "progressive pop", the style emerged from psychedelic bands who abandoned standard pop or rock traditions in favour of instrumental and compositional techniques more commonly associated with jazz, folk, or classical music, while retaining the instrumentation typical of rock music. Additional elements contributed to its "progressive" label: lyrics were more poetic, technology was harnessed for new sounds, music approached the condition of "art", and the studio, rather than the stage, became the focus of musical activity, which often involved creating music for listening rather than dancing.
Progressive rock includes a fusion of styles, approaches and genres, and tends to be diverse and eclectic. Progressive rock is often associated with long solos, extended pieces, fantastic lyrics, grandiose stage sets and costumes, and an obsessive dedication to technical skill. While the genre is often cited for its merging of high culture and low culture, few artists incorporated classical themes in their work to a significant degree, and only a handful of groups, such as Emerson, Lake & Palmer and Renaissance, intentionally emulated or referenced classical music.