My DH asked me to make a guitar cake for his nephew's birthday back in November. The body of the guitar is a vanilla cake, and the neck is RKT. The whole is covered with fondant and the details are 50/50 fondant gumpaste. I didn't put strings on it because I couldn't figure out how to make them realistic looking. I think next time I'll try dental floss stiffened with meringue or RI.