Compound meters are meters in which the beat is divisible by 3.  You can easily tell if a meter is a compound meter by the top number of the time signature. The top number can be any number divisible by 3 that is greater than 3. If the top number is 6, 9 or 12 then the meter is a compound meter. The beat in a compound meter will divide in to 3 equal parts. Since the beat divides in to 3 equal parts, the beat in any compound meter will always be some type of dotted note. Lets take a look at an example in 6/8 to demonstrate this. In a measure of 6/8 it is true that 6 1/8 notes will fill up a measure. But this does not mean that there are 6 beats in 6/8. To determine the number of beats in any compound meter begin by looking at the top number. Since the top number is 6, we know it is a compound meter. To find the number of beats divide the top number by 3. This will show us that in 6/8 there are 2 beats. To find the length of a beat multiply the note value represented by the bottom number by 3. To find this imagine the bottom number as a fraction under the number 1. In this case 1/8 equals an eighth note. Now multiply an eighth note by 3, which will equal 1 1/2 beats, or a dotted quarter note. So the beat in 6/8 is the dotted quarter note, and since there are 2 beats in 6/8 two dotted quarter notes will fill up a measure of 6/8. To help you remember and more easily see this this information visually, you can download the free Compound Meter poster. If you liked this lesson don’t forget to sign-up for the free One Minute Music Lesson newsletter. With your subscription you will also receive a free copy of the eBook "How to Read Music" by Leon Harrell.