"In lieu of a traditional wedding registry, we are asking for donations to be made to benefit Free the Music USA," the couple says in a statement to PEOPLE.
"Philanthropy has been a cornerstone of our relationship since the beginning," they continue. "In the past, we have been blessed to team up with our friends at ACM Lifting Lives, Rising Star Outreach, PS22 Chorus, Refugee and Immigrant Students Empowered and Songs for Sound to enrich the lives of young people. We can't think of a better way to honor our upcoming nuptials than to combine the two things that we love the most: music and helping others."
In fact, Niemann says his bride-to-be's passion for helping people is one of the things he loves most about her. "It's so funny, the little things we can all get upset about," the singer tells PEOPLE. "That's why it's just really cool to see somebody that really thinks of others and wants to make people happy."
And since the couple, who have been together since 2005, is all about helping kids, does that mean they'll have a few of their own someday?
"We'd love to have a family," says Niemann. "Starting a family and making her my wife – that's all part of the deal!"