Adorno's saying that ‘art is the promise of happiness’ radiates into every corner of his work from his aesthetic theory to his critical theory of society. However, it is much misunderstood. This can be seen from the standard answer to the question: in virtue of what formal features do art works, according to Adorno, promise happiness? The standard answer to this question suggests that the aesthetic harmony occasioned by the organic wholeness of the form realized in the artwork contrasts with and throws into relief the antagonistic nature of society. The trouble is that this answer is flatly incompatible with Adorno's historicism and central components of his aesthetic modernism, including his critique of classicism, and his negativism. I propose a re-interpretation of Adorno's thesis that art is the promise of happiness that overcomes these difficulties.