I was shown the malecon on a Saturday night when I was there in Feb. of 2003 by a Dominican AI gift shop worker. It was a wonderful experience to see a large part of the community out in the streets (literally) and enjoying food and music by all ages! I had never seen such a huge music speaker (it took up an entire flatbed trailer!), it shook our tiny cab as we passed by.
We then went down what seemed to be a side alley and entered a Dominican nightclub. It was so dark that our host had to show us to our seats by flashlight and the waiter used a flashlight to show us what we owed on our bill!
I would recommend talking to the staff of the AI where you stay and getting their impressions of what you should see. Knowing a little Spanish can go a long way. Put yourself in their place--wouldn't you be more helpful with someone who attempted English when visiting the U.S.?
Have a great time!
Tondra