You should be able to play just about any music you choose. One of the major limitations is that you may not always be able to play in the key you might choose. Listen to Jean Ritchie if you are interested in the tradtional music that was played on the dulcimer. Folk like David Schnaffer, who was/is Stephen Seifert's mentor, Tull Glazener, Rob Brereton, and Jerry Rockwell have all expanded the concept of what one might expect to hear on the dulcimer. Roger Nicholson, an English mountain dulcimer player, had an excellent recording at one time and he might still be active in music.