Lip Flexibilities - Bass Clef Edition Bai Lins Lip Flexibilities has become (and should be) a standard on the music stands of brass players everywhere, mentioned in one breath with the likes of Schlossberg and Irons. The trumpet professor at the Central Conservatory in Beijing, Bai Lin created an organized set of flexibility studies ranging from elementary to advanced skill levels. Balquhidder now releases a bass clef edition to benefit even more players of cupped instruments.