Metric Modulation: Changing Time Signatures

What is Metric Modulation?

Like modulation, metric modulation is a segue between contrasting musical sections. In the case of metric modulation, it is a transition between two rhythmically different sections.

Imagine that you want to use two different meters within your song. The first is the standard meter, called common time, with four pulses per measure. But in the second half of the song, you want to transition to a meter that uses three pulses. And you want those pulses to be a bit faster than before.

What you can do is gradually hint at the transition earlier in the tune, and then write a section that uses a metric modulation combining the two sections.

This example starts off in common time, but by the end of measure 4, a triplet figure comes into play that hints of a bigger change to come.

Example 1

We’re not psychics, and we can’t predict that the music is about to change meter. Even in the next example, we’ll still tend to hold onto the common time meter a bit, especially because of the two-beat pauses.

Example 2

But now we’ve been hammering on that three-note pattern for some time now. The ear starts to interpret it as something else. Keep in mind that any musicians playing this will probably play the triplet patterns within the conventions of common time so every one of four beats will still sound more prominent. So in some ways it will still not feel quite like a waltz time yet. But now we’re telling them to change time signature.

Example 3

Now that the meter has changed, every aspect of the thing is in waltz time, and now the metric modulation is complete. The ear has registered a hint of something new to come, a gradual transition, and finally has settled into a new groove.

Because the tempo has already increased, the presence of even smaller note units (the eighth notes in the new time signature) will strongly signal to the listener that something about the time has changed.