Rankin-Bass & NBC took a chance in December 1979. The fact that Jack Frost has aired on cable the last several years suggests that gamble paid off.
Jack Frost tells the story of how the winter sprite (Robert Morse, ex-That's Life) became human for a time, largely because he fell in love with a young woman. Of course, there are certain trials & tribulations for Jack to go through, including saving the village of January Junction from a tyrant (Paul Frees, of course). The cast also includes Larry Storch (ex-F-Troop, Ghost Busters), Debra Clinger (ex-Krofft Supershow, American Girls), and a name from the Golden Age of Television, Dave Garroway (ex-The Today Show), in what I think was his only voice-over credit in animation. The special gives narrator Buddy Hackett an avenue to demonstrate his singing ability, which is pretty fair, admittedly, especially in covering Al Jolson's "Me & My Shadow".
Jack Frost was the first special Rankin-Bass had sold to NBC in some time, as I'm not sure if the Peacock Network had actually acquired the sequel to Little Drummer Boy. NBC would get at least one more R-B special, The Stingiest Man in Town, the producers' take on Dickens' A Christmas Carol, with Tom Bosley (Happy Days) & Walter Matthau, a few years later.
Right now, let's scope a little musical action from Pardon Me Pete (Hackett):