So far we've covered many of the common (and a few of the less common) time signatures. In this lesson, we're going to take a look at something called mixed meters (also called changing meters). Music is said to be in changing meters when the time signatures change often during the course of the composition. True, there are works that change meters for different sections of the piece - perhaps the first theme could be in common time while the second theme is in 12-8. But meter changes that last a good long while wouldn't mean that the piece would be considered a mixed meter composition.
The meter changes in a mixed meter composition may follow an organized and repeating pattern. In example 1, you see measures of 3-4 constantly alternating with measures of 2-4. This same concept could be written in three different ways.
One method is to notate the new meter at the beginning of each and every measure (like the first example). Another is to use a time signature at the beginning of the section to let the performer know that the meter changes will follow a particular format (example 2). In this case, the composer would simply write both meters in the first measure, one after the other, to set up the recurring pattern. The advantage of using this method is that the composer and/or copyist saves time and ink by not having to write the signature for every measure. There's an advantage for the performer as well since the page is visually less cluttered with meter changes.
The last option (example 3) is to use a different type of signature that ties two meters together. In this case, the composer is informing you that a single measure is made up of a 3-4 bar plus a 2-4 bar. Notice that there are no bar lines between the two parts of the measure. In essence, this creates a signature that is identical to 5-4 time but will always be phrased as three beats plus two beats (a phrase of two plus three would contradict the meter).
In the majority of mixed meter compositions, the changes don't necessarily follow a pattern, and the composer is free to use any meter at any time. When working without a pattern, each and every change in the meter must be written. There aren't any time signature shortcuts. This requires keeping a close eye on the changing meters as well as on the note values and the position of the notes on the staff.
The most difficult thing about changing meters is remembering what meter you're playing at any particular time. Time signatures work like speed limit signs, in that new speeds take effect at the location of the sign. If you're going through a school zone at 15 mph, you can't go faster until you reach the location of the next sign. If that sign tells you that the speed limit is now 35 mph, that speed stays in effect until you reach the next sign. Time signatures work the same way. If you're playing in a meter of 5-4, each succeeding measure will also be in 5-4 until you see the sign for a new meter.
Throughout this series of lessons, I've suggested that you try to look ahead by keeping your eyes in front of your hands. When looking ahead, you can prepare for what's coming up next. Staying with the driving analogy, you usually keep your eyes several yards in front of your car. If your visual focus is only a few feet ahead of the hood, you won't be able to react to something that may cause you to crash. The same process is required when reading music in mixed and changing meters. It's important to see the meter, react to it and make a mental shift before you actually begin playing the bar. If you don't, then you stand a good chance of "crashing" into the new time signature.
Notice in the two exercises in this lesson that some of the lines end with a time signature. These are called "courtesy signatures" because they give you advance warning that the time signature is going to change at the beginning of the next line.
The two exercises presented in this lesson are examples of mixed meters where the upper value (the one representing the number of counts in each measure) changes. The lower number, representing the note value that receives one count, remains the same. The first exercise uses the quarter note for the value of the count, the second uses the eighth note. For both of these exercises, the speed of the counts should remain constant. Next lesson, we'll look at mixed meters that change the value of the count.