We had a Drupal 7 site setup with a default calendar instance that was displaying content of type 'event'. Due to the limited number of events this site would promote, it was decided to change the navigation from the standard 'Next/Previous' to use drop down menus where the user could choose the month/year they wanted to view.
The original look
Steps to accomplish this
Step 1
First, get your view setup to match the original.