Hal Leonard Corporation is a United States music publishing and distribution company founded in Winona, Minnesota, by Harold "Hal" Edstrom, his brother, Everett "Leonard" Edstrom, and fellow musician Roger Busdicker. Currently headquartered in Milwaukee, Wisconsin, it is the largest sheet music publisher in the world.
Jon Chappell is a multi-style guitarist, composer, arranger, and best-selling author. He holds a master's degree in music composition from DePaul University, served as editor-in-chief of Guitar Magazine, and was the founder and first editor-in-chief of Home Recording magazine. He is the author of several books.
Mark Phillips is a guitarist, arranger, and editor with more than 30 years in the music publishing field. He earned his bachelor's degree in music theory from Case Western Reserve University, where he received the Carolyn Neff Award for scholastic excellence, and his master's degree in music theory from Northwestern University, where he was elected to Pi Kappa Lambda, the most prestigious U.S. honor society for college and university music students. While working toward a doctorate in music theory at Northwestern, Phillips taught classes in theory, ear-training, sight-singing, counterpoint, and guitar.
Desi Serna has built a substantial online platform as an engaging and approachable guitar guru-a guitar player and teacher with more than 10,000 hours of experience providing private guitar lessons and classes. Serna is hailed as a "music-theory expert" by Rolling Stone magazine.