Have you noticed that under some audio conditions, some songs become unrecognizable while others hold up? I noticed it again this morning while taking a shower. I'm on my sister's farm and was using only my iPhone for audio in the shower. The higher pitched noise of the running shower took out certain highs that really threw some songs off big time. I've also noticed this in the car when the sound is turned way down, or when driving in heavy rain.
One thing that happens... Beats created with sounds that have a quick decay on the filter to add some pop to the individual sound, then are heavily compressed. When you remove the highs you are left with more of a pulse after the beat that can change the timing. When you mix sounds of this type with sounds that don't have filters you can actually change the pattern of the rhythm. That is just on drums. When this affect happens to apps, rhythm guitar and other instruments it really messes with a song.
Has anyone else noticed this? If not you must not have a sister who insists on turning the volume down to 1 while riding in a car. Does anyone ever test for this? I know people test their songs on different speakers, but do you test at different levels and simulate different conditions?