Why is it that so many songs sound alike? Is it because we are running out of new combinations of notes? Michael at VSauce does a nice job of laying it all out for you. While there is a limit to how many songs we can create with a given length, we aren't likely to run out of possibilities any time soon. The real issue is that we seem to only like a very small section of the space of all possible songs. Ah yes, once again, we are our own limiting factor. There are a lot of good facts in here and I especially liked the link he suggested to the video below that shows how many songs are lyrics are interchangeable because they use the common meter. Fun stuff!