There you go! It ain't over till the fat lady sings

"It ain't over till (or until) the fat lady sings" is s a proverb. It means that one should not presume to know the outcome of an event which is still in progress, particularly sports.

It is generally understood to be a reference to opera sopranos, who were typically heavyset. The imagery of Wagner's opera cycle Der Ring des Nibelungen and its last part, Götterdämmerung, is typically used in depictions accompanying uses of the phrase. The "fat lady" is thus the valkyrie Brünnhilde, who was traditionally presented as a very buxom lady. Her farewell scene lasts almost twenty minutes and leads directly to the finale of the whole Ring Cycle