In swing rhythm, the pulse is divided unequally, such that certain subdivisions (typically either eighth note or sixteenth note subdivisions) alternate between long and short durations. Certain music of the Baroque and Classical era is played using
notes inégales, which is analogous to swing. In shuffle rhythm, the first note in a pair may be twice (or more) the duration of the second note. In swing rhythm, the ratio of the first note's duration to the second note's duration can range: The first note of each pair is often understood to be twice as long as the second, implying a
triplet feel, but in practice the ratio is less definitive and often much more subtle. In traditional jazz, swing is typically applied to eighth notes. In other genres, such as funk and jazz-rock, swing is often applied to sixteenth notes. ) In most
jazz music, especially of the
big band era and later, the second and fourth beats of a 4/4 measure are emphasized over the first and third, and the beats are lead-in—main-beat couplets (dah-DUM, dah-DUM....). The "dah" anticipates, or leads into, the "DUM." The "dah" lead-in may or may not be audible. It may be occasionally accented for phrasing or dynamic purposes. The instruments of a swing rhythm section express swing in various ways, which evolved as the music developed. During the early development of
swing music, the bass was often played with lead-in—main-note couplets, often with a percussive sound. Later, the lead-in note was dropped but incorporated into the physical rhythm of the bass player to help keep the beat "solid” - the lead-in beats were not audible, but expressed in the player’s motion. Similarly, the rhythm guitar was played with the lead-in beat strummed by the player, but so softly as to be nearly or completely inaudible. The piano was played with a variety of devices for swing: Chord patterns played in the rhythm of a dotted-eighth—sixteenth couplet were characteristic of boogie-woogie playing (sometimes also used in boogie-woogie horn section playing). The "swing bass" left hand, used by
James P. Johnson,
Fats Waller, and
Earl Hines, used a bass note on the first and third beats, followed by a mid-range chord to emphasize the second and fourth beats. As with the bass, lead-in beats were not audible, but expressed in the motion of the left arm. Swing piano also put the first and third beats in a role anticipatory to the emphasized second and fourth beats in two-beat bass figures. As swing music developed, the role of the piano in the ensemble changed to emphasize accents and fills; these were often played on the lead-in to the main beat, adding a punch to the rhythm.
Count Basie's style was sparse, played as accompaniment to the horn sections and soloists. The bass and snare drums started the swing era as the main timekeepers, with the snare usually used for either lead-ins or emphasis on the second and fourth beats. It was soon found that the high-hat cymbal could add a new dimension to the swing expressed by the drum kit when played in a two-beat "ti-tshhh-SH" figure, with the "ti" the lead-in to the "tshhh" on the first and third beats, and the "SH" the emphasized second and fourth beats. With that high-hat figure, the drummer expressed three elements of swing: the lead-in with the "ti," the continuity of the rhythmic pulse between the beats with the "tshhh," and the emphasis on the second and fourth beats with the "SH". Early examples of that high-hat figure were recorded by the drummer
Chick Webb.
Jo Jones carried the high-hat style a step further, with a more continuous-sounding "t'shahhh-uhh" two beat figure while reserving the bass and snare drums for accents. The changed role of the drum kit away from the heavier style of the earlier drumming placed more emphasis on the role of the bass in holding the rhythm. Bebop soloists rose to the challenge of keeping a swinging feel in highly sophisticated music often played at a breakneck pace. The groundbreakers of bebop had come of age as musicians with swing and, while breaking the barriers of the swing era, still reflected their swing heritage. they are also an important feature of
baroque dance and many other styles. In jazz, the swing ratio typically lies somewhere between 1:1 and 3:1, and can vary considerably. Swing ratios in jazz tend to be wider at slower tempos and narrower at faster tempos. In
jazz scores, swing is often assumed, but is sometimes explicitly indicated. For example, "
Satin Doll", a
swing era jazz standard, was notated in time and in some versions includes the direction,
medium swing. ==Genres using swing rhythm==