When you set up your events in ThunderTix, the Mailchimp integration pulls in all of your Mailchimp Audiences. Select the list(s) that apply for that event. When customers buy tickets and opt in to receive notifications from your organization, they will be automatically subscribed to the proper audience(s).
If you have an event that is both "theater" and a "family" show, check both lists. That way, that customer will be subscribed to receive updates from you about future theatrical productions and children's shows.
In addition, you can perform robust searches using our CRM to filter your customer database to a narrow set of parameters. Then, you can "Send to Mailchimp" to view all of your available Audiences. Send the resulting list of customer emails from ThunderTix to the Audience of your choice to create a new subset of customers to send a new campaign to that list.