Complete with 13 chromatic tones, the Lee Oskar Harmonicas Pitch Pipe is useful for singers and choirs (a cappella and accompanied by instruments), and for tuning guitar, ukulele, violin and other types of instruments. The pitch follows the International Standard (a'=440Hz). This Pitch Pipe is designed to either be held in your mouth hands-free, so that your instrument can be adjusted with both hands, or held by both hands.