2 navigation systems in one site

This should be simple but can't find a solution. 

I need to create a site with 2 menu systems. It's a festival with 2 separate events. I'd initially thought creating 2 indexes & having no primary navigation (which would be viewed by both) & then creating links & dragging into each index to build a separate menu for each but that didn't work. 

Any samples or idea would be a great help. 

Thanks 

On a site with two languages, this is exactly how it works. One nav for English, one for another language; only one shown at once.

If you think of the two events as two different languages, you can build it in the same way. @bradgood wrote a great guide that you should find useful: How to setup Multi-language content on any Squarespace template.

Thanks Paul!