Sign up for Newsletter? Have your conctact details changed?

Information about concerts and CD releases:

>Annual program via snail mail, short term invitations by email
(the newsletter is free of charge, you can unsubscribe any time.)
 

In addition to your email address, please also give us your postal address so that we can invite you to concerts in your area, especially regionally.

What is the sum of 4 and 7?