The Monkees were the brainchild of television producers Bert Schneider and Bob Rafelson, who decided to emulate the zany, madcap humor of the Beatles' A Hard Day's Night for the small screen. In September 1965, they placed in ad in Variety for four "folk & rock musicians" to appear in a TV series. Over 400 applied for the job, including Stephen Stills and Harry Nilsson, but as it turned out only one of the four winners, guitarist and songwriter Michael Nesmith, actually saw the ad. Micky Dolenz (who would play drums), Davy Jones (who would sing), and Peter Tork (bass) found out about the opportunity from other sources. Nesmith and Tork had experience in the folk scene; Dolenz and Jones were primarily actors (although Nesmith and Jones had already made some obscure solo recordings).
From the outset, it was made clear that the Monkees were hired to be television actors first and musicians a distant second. There would be original material generated for them to sing in the series, mostly by professional songwriters like Tommy Boyce, Bobby Hart, Carole King, Gerry Goffin, and Neil Diamond. There would be records, as well -- had to be, with that kind of weekly exposure, to promote the tunes -- but the group wouldn't do much more than sing, although the series would give the impression that they played their own instruments.
The TV show was a big hit with young audiences between 1966 and 1968, with slapstick comedy, super-fast editing, and thin plots that could be banded together by almost surreal humor. It wasn't A Hard Day's Night, but it was, in its way, innovative relative to the conventions of television at the time.