One of the most fun event themes that we've seen as a jazz band performing for corporate events around Los Angeles is the Mardi Gras idea. Just saying "Mardi Gras" conjures up a fun time and image.
Technically Mardi Gras is the celebration that happens on the Tuesday before the religious observation of Lenten. It's a time for revelry and indulgence prior to a period of fasting. However, people celebrate the idea of Mardi Gras year round.
To start, create invitations or announcements that reflect this theme. The colors associated with Mardi Gras are gold, purple and green. These colors represent justice, faith and power by the way. Include those colors in any promotional materials. Adding graphics of beads and masks and you're on your way.
For the event you'll need some New Orleans style jazz. We've performed with bass, sax, keyboard and drums for events like this. Vocals are a plus too. Make sure that the band leader has the correct styles and songs to fit the event motif. You want rocking upbeat celebratory jazz.
During the event you can create fun games for people to "win" beads, give a prize for the best costume and create other types of group participation.
If you like, include cuisine from the area for the total package. With that, your guests will feel like they're right on Bourbon Street having great time!
Here's a link to one of the many suppliers of masks, beads and other stuff to make your Mardi Gras event a real hit.