I run a coffeehouse and we are having the same problem. We've been going now for 42 years, but getting the youngsters in is one of the problems we have also and we don't present all that much traditional music. Even when we hire a band or soloist that are young themselves, it doesn't seem to help. Responses given to me by 30 somethings when asked how to draw their age group in? "We don't want to come to a church, we don't like it when the audience is my mother's age and we especially don't like it because there is no liquor for sale". There it is in a nutshell!
Oh well - we will keep on trying!