Very original idea, nicely done, but needs work
I was amazed to dee a dancing tutorial on newgrounds. Since I'm a dancer myself, this made me so happy that I had to vote 3 on this submission, despite of the things that aren't too good yet.
Now for the comments. First the good things:
1. Your music choice was great. The songs really fitted with the dances.
2. Explanation and background info was very good. All very clear and easy to read and understand.
Now the things to improve.
1. The stepping-drawing at the waltz-section is way to difficult for someone who doesn't know how to dance. I do know how to dance, and still I had to look more than 10 secs to understand what you meant with the drawing. It might be better to make the steps kind op appear and disappear. This way, you can make both the leaders and the followers steps visible. You might even want to zoom out and show a whole dance with only the footsteps.
2. As previously mentioned, back-buttons and menu-buttons should be added.
3. It might be a good idea to find a more original way to show the texts. This way, one has to read lots of sentences. Most people here don't want that. If you make it more "movielike" people might be more interested in what you want them to read.
Well, I hope this helps you. I really hope you're going to put some time in this, because it really has a lot of potential. When you finish this, and put the complete version here, I'll review again. I'm looking forward to it. Do your best!!