Noh did not emerge from nothing in the fourteenth century; it drew together and refined performance traditions already centuries old in Japan, most importantly sarugaku, a broad category of popular entertainment including acrobatics, mimicry and comic sketches, and dengaku, field music and dance with origins in agricultural ritual meant to secure a good harvest.
Benito Ortolani's history of Japanese theatre traces the form's deeper roots further still, into shamanistic ritual performance in which a performer's role was understood as channeling rather than depicting a spirit or deity, a function Noh never entirely shed even as it developed into sophisticated literary theatre. The decisive transformation came under Kan'ami, a sarugaku performer of the mid fourteenth century, and his son Zeami, who together refined the form's music, movement and dramaturgy and secured the patronage of the Ashikaga shogun Yoshimitsu, a relationship that gave Noh access to elite audiences, resources and prestige unavailable to its more purely popular predecessors. Zeami in particular left an extensive body of writing on Noh's aesthetics and technique, most famously developing the concept of yugen, a quality of subtle, suggestive beauty that became central to how the form understood its own artistic ambitions. That elite patronage reshaped Noh's content and tone considerably, favoring restraint, symbolic economy and psychological depth over the broader comic and acrobatic material of its sarugaku ancestry, even as the older tradition survived alongside it in a separate comic form, kyogen, performed between Noh plays on the same programs.