Currently, this meetupalliance.com website is in preview mode, there is so much that has to be fixed and added! so I totally understand when people find it confusing to join
1- Go to
http://www.meetupalliance.com/classicalmusicandopera2- Then click on the ADD/START a LOCAL GROUP button
Fill in the information to apply, and select I ALREADY HAVE A LOCAL GROUP under the section "Type of Group".
3- Complete the form and click on the APPLY button at the end after all the information is there.
And you are all set!!
Nestor