Your audience has come to expect that once you reach beat one in four beats, we'll hear the next phrase. Imagine you have a song written in 4/4 time, where you've established that each new phrase begins on beat one and lasts four bars. To create anticipationĪnticipation plays another role in why time signature changes are popular.
Then, in the following measure, you could go back to your previous time signature, back to the comfortable groove. This would give you two extra beats to say the words you need to say in a comfortable way ( song blocking can also help with that). You could extend the measure by changing the meter in that one bar, turning it from a 4/4 bar into a temporary 6/4 bar. Say you have a line of lyrics that just doesn't seem to fit right in your measure, no matter how fast you try to sing it.
