How do I know I need song and playlist object ? And what properties and method do I need?

I am right there with you, but I will attempt an answer for you. from my understanding it may be helpful to think of objects in javascript like containers and the methods are the ability to interact with the contents of said container. If you have a song, you may be able to surmise that you need a container to hold that song, and a method in which to interact with that song that is in your container. At least this is my understanding of this subject so far. So it may be helpful to think of objects like physical objects that you need to put in a container to store and the methods are control knobs and dials that allow you to access your physical object without having to take it out of safe storage Let me know if this helps and let's continue this conversation so that we can ruminate over this subject more so we can get a firm grasp.

.onClick