Radio 1 launched in response to the popularity of England's pirate radio stations. At a time when there were few commercial alternatives to the government-run Beeb, the likes of Radio London and Radio Caroline broadcast the latest pop music from ships parked in international waters off the nation's cost.
The pirate stations took their cues from American Top 40 radio, with chatty deejays, chart tunes and snappy jingles, and Radio 1 assumed the same template.
Artists such as Jimi Hendrix and The Who recorded jingles for the new station and George Martin composed and recorded its theme song, the groovy orch-psych instrumental "Theme One."
"Theme One" was the first music listeners to the new station heard following an initial welcome from BBC Controller Sir Robin Scott. After the theme, chirpy deejay Tony Blackburn came on to introduce the first proper tune of the day, "Flowers in the Rain," by the Move.
"Theme One" was played on Radio 1 at the start of each broadcast day through the mid 1970s and was later featured on the station in a cover version recorded by Van Der Graaf Generator.
You can hear the original version on the highly recommended Produced by George Martin box set.
The BBC is celebrating Radio 1's anniversary this weekend with a "pop-up station" that will replicate Blackburn's first broadcast and air highlights from the station's history. Listen here.