[Plugin: NextGEN Gallery] Compacting gallery images

My website is http://www.kicksndaisies.com/ and I was having trouble with making the Galleries compacted. I have multiple galleries for different events and want them posted similar to the “Spain” example from this: http://dpotter.net/technical/2008/05/nextgen-gallery-review-displaying-images-album/

For instance (on my sidebar), i would like to show one event from concert 11-4-10 shown as a single thumbnail and when you click on it, the 20 images from the event will come up. Therefore since I have a total of 2 galleries, there would be two thumbnails that would show up on the sidebar, but when you click on either of the thumbnails, all of the images from that particular event would come up. Sorry for the broken explanation, let me know if have further questions, and am really looking forward to your help!
Thanks in advance