Where did the saying "It ain't over until the fat lady sings" come from?
Often mistakenly attributed to N.Y. Yankees Hall of Famer Yogi Berra—his expression was "it ain't over till it's over"—this popular quote originated in the following form:
The opera ain't over until the fat lady sings.
According to an article in the Washington Post on June 3, 1978, San Antonio sports writer/broadcaster Dan Cook first came up with that proverb about three years before, in response to Ralph Carpenter's statement that "The rodeo ain't over till the bull riders ride." According to Cecil Adams, Cook says he first used it in a column around 1976, but we haven't been able to confirm that.
What's certain is how the expression was popularized. Cook said it on television in 1978, when the San Antonio Spurs were behind in a series with the Washington Bullets. The Washington Bullets' manager, Dick Motta, repeated it, and was widely quoted by the media. By the time the Bullets came from behind to win the finals that year, the saying was on thousands of T-shirts, "fat ladies" were coming to games to cheer the team on, and the proverb's popularity was firmly cemented.
(Motta, who had a solid grasp of grammar, was originally quoted as saying "It's not over... It's like an opera. It doesn't end until the fat lady starts singing and that hasn't happened in this one yet." It immediately reverted to Cook's punchier version in retellings.)
Finally, it should be noted that a Southern proverb, "church ain't out until the fat lady sings," has been found in a 1976 publication. It's not certain which expression came first, and whether one was influenced by the other.
—The Fact Monster