In 1925, Theo Charlier published his 36 Études Transcendentes with Buffon-Crampon Publishers in Liège, Belgium. Based on his orchestral and teaching experiences, he felt the need to provide himself and his students with pedagogical materials to propel them to higher levels of technical and musical proficiency. That he succeeded in his aims is beyond doubt. This collection of etudes has been studied by trumpet players for nearly 100 years and they are as relevant now as when they first appeared.