Written documents were a space for (re)production of established powers, perpetuating a certainly incomplete (and, therefore, biased and distorted) image of the reality of cultures and times. Information centers (or, still better, memory centers) usually acted as instruments of that process, or as (in)conscious accomplices of it. The voices and the thoughts that did not obtain a space in the shelves disappeared with their owners; only a tiny fraction of human reality transcended through the written words.
Popular tradition has been totally neglected by libraries and archives throughout history, except for those traditional elements that were included in literature, classical music or academic art (especially during romantic and nationalist artistic periods). The development of sound recording technologies (from the wax cylinders developed at the end of the 19th century onwards) allowed works of recovery of artistic and oral expressions within anthropology, linguistics and ethnology. The appearance and evolution of the audiovisual media improved these registers and their inclusion into history, politics and sociology. Oral history –a resource already used by Thucydides and Herodotus in classical Greece– witnessed a renaissance since World War II. The testimonies of the participants in the different scenarios of the great conflict allowed a different understanding –more complete and at the same time more complex– of crucial events, opening the doors to experiences in other places. Spanish miners and fighters, French anarchists, Latin American guerrillas and trade unionists, Brazilian sem-terras and others would provide alternative, personal and unique appreciations, enriching the understanding of specific events.
Overcoming sexist and ethnocentric limitations, the range would later expand with contributions made by social anthropology (aboriginal communities), sociology (rural populations) or studies of gender and sexuality (women and homosexuals). Thus, oral history archives or "archives of words" were born to became reservoirs which, usually separated from libraries, are concerned with preserving, organizing and studying this valuable intangible collection.
The development of digital memories and channels for data transmission improved the management of information and the organization of knowledge, including audio and audiovisual supports. Slowly, oral tradition has begun to be included in specialized libraries and documentation centers, and although there is a notable lack of library training in the management of this type of knowledge, a number of international recommendations concerning cultural diversity and intangible heritage encourage the generation and growth of collections that preserve and disseminate the oral expressions of different cultures and peoples. For oral tradition includes all that human experience over which a person is able to express, which is a vast range of knowledge. The variety of individuals who can provide this sort of material is also wide, covering all ages, genders, cultural and educational levels, ethnic origins, currents of thought and creeds. In this sense, orality is much more inclusive than writing.