Wow this is something I never realized. 1.It rose out of the basket and began to follow the movement of the pipe. Correct (suggests that the pipe only does one kind of movement) 1.It rose out of the basket and began to follow the movements of the pipe. Correct (suggests that the pipe does many different movements. For example: It moves up and down, as well as side to side) 2.It obviously could not tell the difference between Indian music and jazz! Correct (suggests that there is one difference, or one major/primary/main difference) 2.It obviously could not tell the differences between Indian music and jazz! Correct (suggests that there is more than one difference) These differences are pretty subtle/small. I think if a native English speaker just read them quickly they would not notice a difference in meaning. For all intents and purposes, you could say them either way, and it wouldn't be strange or confusing. The words "difference" and "movement" are both count nouns. All that means is that you can put a number right in front and it will make sense. For example: There are 2 movements. There are 3 differences. Non-count nouns cannot be counted without adding words. For example: I ate 2 rice. WRONG I ate 2 grains of rice. CORRECT These nouns will just have to be memorized. In general things that don't have clear units to distinguish are non-count such as liquids. Side note: Your question "why here don't use movement?" is wrong. Here are some ways you can say that: Why did they use the word "movements" instead of "movement?" Why did they say "movements" instead of "movement?" Why is "movements" used here?

In both those cases, you could use either plural or singular. Which to use depends somewhat on the situation. If you used movement, you would suggest that there is just one type of movement. Perhaps he just moved it back and forth. If you use movements, you are suggesting that it is moving in several different ways, perhaps up and down and sideways. But those are just suggestions, as I said, you could use either. Similarly, we humans could probably list several differences between indian music and jazz, if we were considering things like tempo and key signature (I'm guessing, I don't really know!) But it's a snake, so perhaps we don't expect it to be that clever, and able to recognise several differences. It might be able to know that it is one or the other, so, one difference. 'tell the difference' is also something of a set phrase. It just means 'distinguish'.