I don't know when the term "destination TV" was first coined, but one of the earliest manifestations of the concept for me was in 1967-69, when CBS aired The Smothers Brothers Comedy Hour.
A show that packed a satirical punch so hard it is said Richard Nixon wanted it off the air, it was the baby of Tom and Dick Smothers and their uber-talented stable of writers, which included Steve Martin, Don Novello, Rob Reiner, Pat Paulsen, Bob Einstein, his brother Albert Brooks, and the head writer, Mason Williams. Week after week, the Smothers crew used comedy to skewer the Establishment and give voice to the counterculture.
And did it ever succeed - the censorship battles the brothers waged with CBS are legendary. After wising up to Tom Smothers' habit of turning in the shows too late to be edited before airtime, the network insisted on receiving full episodes days in advance for review by the censors. This was something that everyone in their audience knew about - that's how public it was. Tommy and Dickie were were always my heroes for never surrendering - until they were summarily thrown off the air on bogus breach of contract charges.
But back to the music. In those days it was not customary to present music on variety television unless it was something people were already familiar with, so there was no place for artists to perform new songs for a mass audience before they became hits. No place, that is, until the Smothers Brothers gave them one.
The Smothers' dedication to giving exposure to new artists did not go unnoticed by A&R executives from Warner Brothers-Reprise, which was establishing itself as a label that carried singer-songwriters, a category which had more or less fallen by the wayside during the early years of the British Invasion.
Williams was a folksinger-guitarist turned comedy writer (and the creator of the loopy theme song for the show). For his first album, one of the tracks involved no singing at all. It was called Classical Gas, and it became a smash hit, waking young people up to the beauty of instrumental guitar music.
Described by Williams as "half flamenco, half Flatt & Scruggs, and half classical," Classical Gas was a bonanza of rhythmic changes, and is considered by many to be a tutorial unto itself for learning to properly fingerpick. What was at best conceived as a novelty song became a classic.