What features are in blues music?

Answer 1

Many are based on the 12 bar blues (I-I-I-I-IV-IV-I-I-V-IV-I-I, with each being for one bar), although a16 bar blues has also been developed. Some more modern Blues Music, such as rock and roll, will use the 7ths of each of these chords. The harmony of traditional blues music tended towards plagal, or the sub-dominant. Listen to Muddy Waters or Jimmy Reed. Some however, drone on the tonic (I) while the singer changes inflection to make it appear as the song is moving to IV and V. Example would be Robert Johnson.

The tonality of the blues is predominantly major, with the inclusion of blues notes (flattened (not flatted) 3rds and 7ths (a little jazzy)). Technically, this really isn't correct, as the Blues is a descendant of African music, and that isn't built around the major and minor scales. It can also use the Western adaption, the 'blues scale'; this explanation assumes 'tonic' as the tonic of a Western major scale: the tonic, flattened 3rd, 4th, sharpened 4th/flattened 5th, natural 5th and flattened 7th. Therefore, the blues scale on c will use the noted C, E flat, F, F sharp/G flat, G, B flat.

It's based on an oral tradition, meaning that it is not passed down to the next generation on paper, but by mouth. The (almost entirely black American) history of the blues can be orally traced back as far as 1860, but the form was popularized during the 1910s. The composer W.C. Handy ('St. Louis Blues', 'Basin Street Blues') was particularly influential.

One of the most important features of the Blues is called "call and response." This is directly from African music tradition. The singer sings a line, pauses, and repeats the line, with subtle changes (it's the best description I could write). This can also occur between a singer and instrumentalist, with either, or both improvising. If the singer improvises, they may often employ a technique called scat singing (Louis Armstrong had a particularly exceptionable ability to do this) in which the pitch and rhythm were improvised and the lyrics were random syllables such as 'Doo-dy doo-da yay'.

Bessie Smith and Billie Holiday are notable examples of blues artists. Blues is, and was, often incorporated into jazz as a system of improvisation. In more modern times, composers such as George Gershwin and the awesome British composer Michael Tippett have used the blues, or variations on it, but these works often use 'blues' in the sense of a 'bluesy mood' - sad or melancholy - incorporating some aspects of traditional blues rather than adhering strictly to the 'blues rules'.