Slow jazz song of lamentation, generally for an unhappy love affair. Usually in groups of 12 bars, instead of 8 or 16, each stanza being 3 lines covering 4 bars of music. Tonality predominantly major, but with the flattened 3rd and 7th of the key (the ‘blue notes’). Harmony tended towards the plagal or subdominant. The earlier (almost entirely Negro) history of the blues is traced by oral tradition as far back as the 1860s, but the form was popularized about 1911–14 by the Negro composer W. C. Handy (St Louis Blues, Basin Street Blues). Composers such as Gershwin, Ravel, Copland, and Tippett have used the term to indicate a blues‐type mood rather than a strict adherence to the form. Among notable blues singers were Bessie Smith and Billie Holiday (though Holiday's main repertoire was pop music).