Wilhelm Keller (1920-2008) was a university professor, music teacher, composer, musician and author. Keller studied music, music education and philosophy in Salzburg, Innsbruck, Leipzig and Münster. He was teacher of music theory and song writing at the Mozarteum in Salzburg. Keller was also a lecturer in music theory at the Music Academy in Detmold, and a lecturer in music education at PH Lüneburg. In 1962 he returned to Salzburg, at the invitation of Carl Orff, where he helped establish the Orff Institute built at the Mozarteum. Keller authored "Orff Schulwerk: An Introduction to Music For Children" as well as his own similar pedagogical series titled "Ludi Musici".