Syncopation and off-beats · Music theory
Accents out of place: off-beats and syncopations, regular and irregular, and the pickup.
Strong and weak beats
Within the measure, some beats weigh more than others. In 2/4 and 3/4 the first is strong and the others weak; in 4/4, the first is strong, the third semi-strong and the second and fourth weak. The same happens within each beat: its first half weighs more than its second.
Music sounds predictable when the important notes fall on those points of support. Syncopation and off-beats are the two ways of contradicting them.
Three kinds of accent
The metric accent belongs to the meter itself: the strong beat weighs even if nobody marks it. The dynamic accent is played louder, and written with a sign. The agogic accent comes from duration: a long note sounds important. Syncopation works by making the last two coincide where the first does not expect them.
That hierarchy repeats at every level: within a measure there are strong and weak beats, within each beat, strong and weak halves, and so on.