With upbeat songs and catchy lyrics, the 1960s band The Swingin’ Six helped usher in a new era for the United States Postal Service. Though you’ll have to scour the obscure corners of the internet to find their tunes, their influence lives on in every piece of mail you send: The Swingin’ Six, along with a handful of other musicians, helped introduce the American public to the five-digit ZIP codes the Post Office still uses today.

The History of ZIP Codes

In the 1940s, only large cities and urban areas had postal zone codes. As the volume of mail doubled within the next 20 years, thanks to the postwar boom, urban growth, and the rise of business mailings, USPS (then called the United States Post Office Department) decided to implement a new system: The Zone Improvement Plan (ZIP), which helped organize and process mail by dividing the country into geographical areas. Each area was assigned a specific numerical code. As Lynn Heidelbaugh, curator of the History Department at the Smithsonian, tells Mental Floss, this also allowed for future computerization.

The Post Office knew it might need help getting the American public to adopt the code. To better promote the new system, it harnessed the efforts of artists like The Swingin’ Six.

In 1967, USPS premiered a 15-minute public service announcement, “ZIP Code with the Swingin' Six,” which was broadcast on local TV channels. Amid quirky skits like cavemen bonking each other on the head and a story of love lost and won through mail, The Swingin’ Six added humor and verve with their five songs about ZIP codes. Through a skit involving exercise, for example, the members of the band explain what each of the digits means, and why the Post Office needed to implement these “five trailblazing numbers.” 

The Swingin’ Six

The music video wasn’t the Swingin’ Six’s musical debut. The six members—Steve Burnett, John Fisher, Pat Lanigan, Richard Neives, Ann Rachel, and Carol Richards—had recorded a 1966 album called For the First Time for Decca Records. It included songs like “Pack Your Bag” and “Bad News.” Musicologist Gary Theroux described the band as having “a Kingston Trio/Mamas & the Papas type sound.”

The Swingin’ Six were only one part of the larger ZIP code campaign. Other efforts included the creation of a cartoon mailman mascot named Mr. Zip (who also makes an appearance in the video) and a “Zip-A-Dee-Doo-Dah” ditty by actress Ethel Merman. Another band, The Five Americans, did well with their ZIP code song: In the fall of 1967, “Zip Code” climbed to #36 on Billboard magazine’s “Hot 100” singles charts over a seven-week run.

Despite the ZIP code campaign's success, The Swingin' Six's time in the spotlight was short-lived. “The Swingin' Six was a perfectly competent, good-looking and good-sounding act which unfortunately never managed to connect with any material with hit potential,” Theroux tells Mental Floss. Though the group appeared twice on TV's The Mike Douglas Show in 1966, they soon broke up. “When a group's records don't sell, they tend to disband pretty quickly,” Theroux says.

The group may not have achieved pop-folk stardom, but the zany ZIP code video they starred in continues to delight those who stumble upon it.