The document discusses various vocal tones and techniques for singing, including thin fold and thick fold tones suited for different vocal ranges, as well as twang, aspirate, belt, head voice, growl, attack, and release techniques. It provides descriptions of how to produce each tone along with examples of artists who exemplify their use. The source is a chapter from the book "Popular Singing" by Donna Soto-Morettini of the Central School Speech & Drama and Liverpool Institute for Performing Arts.