Bai Lin Lip Flexibilities (for all brass instruments) A bestseller since its publication in 1996, this book of flexibilities studies now ranks at the top of every trumpeter's library holdings. Bai Lin was Professor of Trumpet at the Central Conservatory in Beijing, China. He has composed an extraordinarily well organized 40-page book of flexibility studies which spans the elementary to advanced levels. This new standard text for brass embouchure flexibility deservedly joins the pantheon of other such studies by Schlossberg, Irons, Colin, Smith, etc. Atpl Human Factors Pdf To Excel.