1 is also regular, throughout, the light eighth-notes occupying the light third beat, and the heavy dotted-quarter the heavy pulse (in the third measure).

Ex.

2 is strikingly definite in rhythm, because the time-values are so greatly diversified; and the arrangement is regular.
On the other hand, the following is an example of irregular rhythm: [Illustration: Example 4.

Fragment of Beethoven.] The longer (heavier) tones are placed in the middle of the measure, between the beats; the tie at the end of measure 3 places the heavy note at the end, instead of the beginning, of the measure, and cancels the accent of the fourth measure.

These irregular forms of rhythm are called syncopation.