Music cognition is an interesting thing. E.g., consider a typical electronic dance music crescendo in common time. Say you've got four beats to a measure. Then

Music cognition is an interesting thing. E.g., consider a typical electronic dance music crescendo in common time. Say you've got four beats to a measure. Then you've usually got the first half of a phrase in 4 measures, with the second half of the phrase happening in the next 4 measures. Now, imagine that this first 8-measure phrase starts a long crescendo that will eventually lead to the "beat dropping"-- i.e., the percussion finally gets introduced. It's pretty easy to imagine an additional 8-measure phrase right after the first one, and being able to hear how they pair together in the unfolding of the crescendo. Going further, there are a lot of these buildups where two 8-measure phrases are followed by yet another group of two 8-measure phrases to create a larger pair of 16 + 16 measures. So you have: 1. hierarchy or 4 beats to a measure 2. groups of 8 measures phrases 3. pairs of phrases in 8 + 8 measures 4. pairs of pairs in 16 + 16 measures If you drop the beat after 16 + 16 measures, most listeners would be able to track where they are at each moment of the long crescendo. In other words-- even if you don't know when the beat is going to drop, you can still hear when you start the second group of 8 measures, or when you being the second group of 16, or when you're at the end of the first phrase, etc. The music-listening apparatus in your brain can track that stuff. The question is: how far out can you take these groups of measures before the listener loses where they are in the larger rhythmic hierarchy?