This post is inspired by an article by harpist Anne Roos that appeared in Folk Harp Journal. However, I believe it is applicable to all types of music - instrumental, vocal, sacred, and secular. Anne noted that when she was playing the Ren Fair circuit, people stopped and listened (and threw money in her hat) when she played Greensleeves and Scarborough Fair. Her other charming but obscure Renaissance pieces just kept them moving on. She developed a million ways to play those two tunes so that she could keep coming back to them.
I had a similar experience playing an assortment of Irish and Scottish tunes mixed with early Spanish harp music. My violinist and I noticed smiles and nods for the Celtic. We weren't playing for money that time, but boy, if I want to put out the hat next time, we know what to play at 80% of the time.
Well, how does this apply to everyone else? Gosh, folks, give them some familiar tunes, hymns, chants, whatever! Mix these in with your new stuff and let some of the new work move with repetition into the familiar category.
Hey, ya ever hear of a "cover band"? There's a reason people like them. And yes, that's me behind the harp.