Swing (i).

A quality attributed to jazz performance. Though basic to the perception and performance of jazz, swing has resisted concise definition or description. Most attempts at such refer to it as primarily a rhythmic phenomenon, resulting from the conflict between a fixed pulse and the wide variety of accent and rubato that a jazz performer plays against it. However, such a conflict alone does not necessarily produce swing, and a rhythm section may even play a simple fixed pulse with varied amounts or types of swing. Clearly other properties are also involved, of which one is probably the forward propulsion imparted to each note by a jazz player through manipulation of timbre, attack, vibrato, intonation or other means; this combines with the proper rhythmic placement of each note to produce swing in a great variety of ways.

J. BRADFORD ROBINSON