'Let It Snow' Song -- Songwriters Say Screw That ... Make it Rain, Bitch!

The 2 famous songwriters who penned one of the most famous Christmas classics ever are at each other's throats -- beyond the grave -- 70 years after they dropped the tune.

"Let it Snow! Let It Snow! Let It Snow!" -- which has been covered by Garth Brooks, Patsy Cline, Dean Martin, Carly Simon and many others -- has made untold millions over the years.

The songwriters -- Sammy Cahn and Jule Styne -- are long dead, but their estates are squabbling over a fortune. Styne's widow made a claim against Warner/Chappell Music for more than $2 million in royalties, and Cahn's estate jumped in because they wanted a piece of the pie. So no money is getting paid out to anyone until the dust settles. And that's what just prompted Cahn's widow to sue Warner.

By the way, Sammy Cahn wrote all sorts of classics, including "Love and Marriage" and "Call Me Irresponsible." And in case you're not old, "Love and Marriage" was not written for "Married with Children."

FUN FACT: "Let it Snow" was written in JULY, 1945, during a heatwave ... so the song was about wishful thinking, not XMAS.