When “Curb Your Enthusiasm” returns for its much-anticipated 10th season it does so with it a musical theme that’s a prime example of recognizable sonic branding and has become synonymous with comedy in our complicated times: “Frolic” by composer Luciano Michelini.

But surprisingly, this comic march for tuba, mandolin and piano wasn’t specifically written for the series. Rather, it was composed as a throwaway piece for an obscure Italian film (“La Bellissima Estate aka The Beautiful Summer,” a 1974 melodrama starring Senta Berger), wound up in a music library and was accidentally discovered by comedian-writer Larry David.

In a previous recounting, David spoke of hearing it in a bank commercial. “I love that, where’d they get that from?” he thought at the time. “The commercial ran for a week and I never saw it again. Then I had my assistant research it — it became this whole ordeal to get the name of the bank and the music, and finally she tracked it down. I just put it away for sometime when I would need it.”

When, in 2000, David launched “Curb Your Enthusiasm,” he remembered “Frolic,” and series editor Steve Rasch found it at what was then known as Killer Tracks, a production music library which is now Universal Production Music.

“‘Frolic’ was in a catalog we called the RCA-L library, which was basically Italian film music from BMG,” says Carl Peel, who is now vice president of repertoire and music production at the company. “We were owned by BMG at the time and we rep’d this catalog of old Italian film music from the ’50s, ’60s and ’70s. ‘Frolic’ was on one of those discs.”

Peel provided “Frolic” and “a bunch of music that was related, with the same sort of Italian circus-y vibe,” he added. Much of the music over the series’ past nine seasons, also licensed from Killer Tracks, originated with such Italian composers as Luis Bacalov (“Il Postino”), Armando Trovajoli (“Marriage Italian Style”), Piero Umiliani (“Big Deal on Madonna Street”) and others.

But “Frolic” remains the series’ best-known piece. “It’s one of the most recognizable of our pieces out in the culture,” says Peel. As David noted: “It just sort of introduces the idea that you’re in for something pretty idiotic.”

“Curb Your Enthusiasm” Season 10 premieres Jan. 19 on HBO.