I think I’ve hit upon a possible solution for eliminating duplicate title tags on recurring events. Using Yoast SEO, you can modify the variables in the template that creates the event post titles. So I can insert the variable %%date%% into the template after the existing %%title%% variable, and my title will say, for example, “Live Music May 27, 2016”.
Unfortunately, this solution inserts the date the event post was created, not the actual date of the event.
Currently the only standard Yoast variable I’ve found that gives me a unique title tag for each event is %%id%%, but that doesn’t result in a user-friendly title. Here are two recurring events that use the ID tag to generate the title:
https://sorsowineroom.com/events/live-music-2/2016-12-27/
https://sorsowineroom.com/events/live-music-2/2016-12-13/
Another Custom Field Name variable available within Yoast is this: %%cf_<custom-field-name>%%. Can you identify the custom field name for the event date within an event post, so I could plug that into this variable?