Woodwind or brass instrument? The categorization of wind instruments is not always easy to understand. Although a saxophone consists mostly of metal it is considered a woodwind instrument, as is the flute or a plastic recorder. Medieval brass instruments although manufactured mainly from wood are considered to be a brass instrument as they feature a brass mouthpiece therefore it is related to the trumpet and trombone in terms of tone. Clarinets, oboes, bassoons, saxophones, flutes and even organs and whistles are considered woodwinds as their tones are created by vibrating pieces of wood or reeds.