Crook, in brass musical instruments, detachable piece of metal tubing inserted between the mouthpiece and the main tubing or in the middle of the tubing to lengthen the air column produced. This manipulation allows the player to obtain notes not included in the harmonic series of the original air
Four Centuries of Musical Instruments: The Marlowe A. Sigal
Crook (music) - Wikipedia
Serpent - Schubert Club
List of Common Woodwind Instruments - Instrumentful
Russian Bassoon (Bass Horn), probably French
Totority 1pc Sax Bend Neck Golden Sax Neck Part Saxophone Neck Replacement Saxophone Neck Cork Saxophone Accessory Saxophone Bending Neck Saxophone Gifts Bent Pipe Bent Neck Brass : 1: : Books
Bach Stradivarius Cornet - Shepherd's Crook
Crook, Brass, Woodwind & Wind Section
Classical Horn Crook Combination Chart — Natural Horns by Richard
Parts of the Bassoon The Instrument Place