“Simmer down,” Sheriff Andy Taylor would say when someone got overly excited on “The Andy Griffith Show.” But judging from a recent lawsuit filed over the show's iconic whistled theme song, simmer is definitely up.

The heirs of Earle Hagen and Herbert Spencer, the composers of “Theme for 'The Andy Griffith Show,'” are suing CBS Television Distribution, claiming the media group is using the theme without a license on DVDs of the TV show. According to The Hollywood Reporter, the suit argues CBS is relying on a 1978 agreement that doesn't include rights to the series on home video or other modern media.

“CBS has refused to enter into a new agreement with Plaintiffs to authorize its exploitation of the Theme in additional media or to otherwise cease conducting such unauthorized exploitation,” the complaint reads. “To the contrary, plaintiffs have since learned that CBS has licensed the Series to digital services such as iTunes and Amazon for distribution and public performance.”

Earle Hagen and Herbert Spencer registered the copyright to the theme song in 1960. The rights to the song were later transferred to their partnership, Larrabee Music. When both writers died, the copyright came to be in the hands of Hagen Publishing Group Inc. and The Diana R. Spencer Trust, with partial copyright ownership given to the Hagen Children's Trust and the Hagen Decedent's Trust.

The plaintiffs are seeking an injunction to stop CBS from using the theme, as well as attorneys' fees, and actual and statutory damages.

“The Andy Griffith Show” ran on CBS from October 3, 1960, to April 1, 1968. It starred Andy Griffith is Sheriff Taylor, Don Knotts as deputy Barney Fife, and a young Ron Howard as Taylor's son Opie.

The theme for “The Andy Griffith Show” also goes by the title, “The Fishin' Hole,” and includes lyrics by Everett Sloane that are rarely heard outside the official TV version: “Well now, take down your fishing pole / And meet me at the fishing hole / We may not get a bite all day / But don't you rush away.” Earle Hagan has said he thought the show required a simple melody for its theme song, and wrote it in 15 minutes. When he recorded it with his bass player and drummer, “I whistled the tune myself,” he said.