Back in 1962, when Johnny Carson was named to take over as host of The Tonight Show in New York, he needed a theme song. Carson quickly found one, and for the next 30 years, Johnny's Theme—with its drum-driven intro, brassy fanfare and swinging arrangement—became associated with late-night programming, adult humor and jazz. Most of the band's musicians were East Coast jazz artists and, later, the West Coast jazz scene, and Carson was a big fan.
But while Johnny's Theme conjures up images of a suave pencil-drumming host, multicolored curtains and a laughing sidekick, the song actually was a cover of a cover of a cover of a cover.
The original melody was written by Paul Anka in 1959 for trumpeter and bandleader "Tutti" Camarata and released on Disney's Vista label as Toot Sweet—a pop instrumental that featured a harpsichord. Camarata also was Annette Funicello's producer, so when she needed an album of love songs to help her transition from TV's The Mickey Mouse Club to Disney's teen movies, Anka was asked to write a dozen songs. The result was Annette Sings Anka (Vista). For one of the songs, Anka took Toot Sweet's melody, added lyrics and renamed it It's Really Love. In 1959, Anka and Funicello were dating, and Funicello's earlier hit, Tall Paul, had been a play on their public teen relationship.
At the time, Europe was going through a modified teen craze similar to the one in the States—albeit a bit modified and stiffer. While the French and Italian movie industries didn't have beaches with surf, there were swimming pools and motorscooters. In Faibles Femmes [Women Are Weak], a 1959 French film made in Paris and overdubbed for Italian teen audiences, the movie needed a song by a male teen heartthrob to suit the storyline. So Anka recorded his own It's Really Love for ABC-Paramount and the song appeared in the film.
Before taking over The Tonight Show in 1962, Carson decided to adapt the nearly forgotten It's Really Love—provided he could re-write the lyrics. This credit allowed him to claim 50% of the song's performance royalties on TV—even though the lyrics were never used on the show.