Note: Ostinato rhythms in pop music. Cantometric analysis of hit songs so far reveals none with drum and singing. All have strings, percussion, and aerophones. 75% of time there is melody in orchestra of this rhythm, or more elaborate rhythms played over this figure (counterpoint). Orchestra accompanying voice or visa versa is not the same as polyrhythm. It's more than a simple accompaniment. Usually vocal line is the most contrapuntal line. Unison frequent between voice and fiddle. If, say, clarinet plays an independent line code both counterpoint and unison. Heterophony and shadowing. When a singer is going to sing heterophony, then the orchestra is playing in rhythm, but singer takes liberties. Late times of rock and roll: discoordinate (talking and screaming), code as non-pattern. Stanley Brothers "Lonely Island," isorhythmic. Notes changing on every phrase. Playful rhythms, strict temperament, and blue notes, same pattern as bluegrass. Also found in white teams. Bluegrass has modal quality, especially in part singing. Orchestra has modal harmonies, as well. Little chromaticism in white music, lots in black music. Not much in bluegrass music. Black 1970s groups such as Commodores and Chambers Brothers characterized by diatonic modal qualities just like bluegrass. Some remarks on 1920s material, contrast between black and white music. "Shadowing" - a stage technique. Orchestral tone in white music is strict temperament. Both have isorhythmic melodies. Comparison of a 1920s recording of "Sensation Rag" by the Original Dixieland Band and "Dippermouth Blues," played by King Oliver's Creole Band. Original Dixieland Band sounds improvised but in fact consisted of three memorized 16-bar sections - A, B, and C - that are played exactly alike, shuffled at random and with no improvisation, but block chords in contrary motion, like hymns. King Oliver's blues is an organic whole of three 12-bar sections with no repetition and constitutes collective and solo improvisation with free counterpoint.