Dictionary of Music - Birding America

ibab 349ment, including melodic movement (the movementof a melody up or down in pitch). Others includealso harmonic rhythm, that is, the pattern of harmonies(chords). Most, however, define rhythmpurely as a matter of notes in time, no matter whattheir pitch, and consider music to be made up ofthree basic elements: melody, rhythm, and harmony.Nevertheless, in practice these elements cannotreally be separated, since each influences theother.Since the sixteenth century or so, the rhythm ofmost Western (European and American) music hasbeen based on patterns of accents and time values(meters). For three centuries prior to that, musicaltime was organized by means of MENSURAL NOTA-TION, and before that it was governed by the RHYTH-MIC MODES. All these systems are more or less basedon the idea of regularly repeated beats. Most Asianmusic, on the other hand, is not organized by meansof regularly recurring accents, nor are the lengths ofthe tones necessarily measured (time values). Such asystem is called free rhythm, and some examples ofit can be found in Western music as well—in Gregorianchant, in operatic recitative, and in generalwherever music imitates the rhythms of ordinaryspeech rather than those of metrical poetry. (See alsoACCENT; TIME SIGNATURE.)rhythm and blues A style of black Americanpopular music that combines elements of blues andjazz. Developed in the United States in the 1940s, itbegan mainly as dance music. Loud and blaring inperformance, with heavily punctuated, drivingrhythms, it is generally performed with electronicallyamplified instruments (among them guitars)and a loud tenor saxophone. Rhythm and blues issaid to reflect the haste and clangor of city life as itmust have seemed to many blacks who came fromrural areas to find work in factories during WorldWar II. It flourished until about 1960. Importantrhythm and blues artists were Muddy Waters, JoeTurner, B.B. King, Chuck Berry, Little Richard, andRay Charles. In the hands of white performers,rhythm and blues became rock. Black performers,on the other hand, turned rhythm and blues intoSOUL. Abbreviated R and B. (See also BLUES, def. 1;ROCK; FUNK.)rhythmic modes A system of organizing musicaltime, based on the meters of classical Greek andLatin poetry, that was used from the middle of thetwelfth to the middle of the thirteenth centuries.There were six rhythmic modes, consisting of patternsof two time values, the brevis (double wholenote) and the longa (twice or three times as long asa brevis). The six modes were: I. longa–brevis;II. brevis–longa; III. longa–brevis–brevis; IV. brevis–brevis–longa; V. longa–longa; VI. brevis–brevis.Reducing the time values to modern ones, with alonga equal to a half note and a brevis to a quarternote, they would be:Music during this period was written in neumesrather than notes (see NEUME), and the modes wereindicated by ligatures, short lines linking theneumes. The opening ligature of a compositionshowed what rhythmic mode was to be usedthroughout; this rhythmic pattern then was usedmore or less consistently in all the voice-parts of thecomposition. A longa was held three times as longas a brevis except when it was immediately precededor followed by a brevis (as in modes I, II, III, andIV). About the middle of the thirteenth century therhythmic modes were replaced by another system,called MENSURAL NOTATION, which eventuallydeveloped into the present-day system of indicatingtime and rhythm in the seventeenth century.RhythmiconSee under COWELL, HENRY.rhythm section In jazz and other kinds of popularmusic, the instruments in the ensemble that markthe rhythmic pulse. They usually consist of traps,percussion instruments, a plucked double bass orelectric bass, and sometimes also guitar and/orpiano.ribabAnother name for RABAB.