Gregorian chant belongs to the oldest music being preserved in such scope till present, moreover it is still performed but also is one that mostly influenced the history and presence of music. For the reason it is important for C/G Anglo Concertina (20-Button) players to meet this kind of music. Includes: Veni Creator Spiritus, Stabat Mater, Veni Sancte Spiritus, Pater Noster, Missa XI, Ave Maria, Ave Verum Corpus and many more... Check out samples from book: http: //osos.sweb.cz/Sarek-Guitar-and-Guitalele-preview.pd