Lips of Steel Baldwin, 22 Endurance test for Trumpet. David Baldwin has created a book of etudes packed full of exercises for buildingendurance and strengthening the embouchure, playing with musicaity while maintaining the strength to do so is a vital aspect of trumpet technique, and has yet to beaddressed fully in method book form until now, Lips of Steel is sure to become an essential part of the trumpet player's curriculum. For Intermediate students.