Yamaha's YFL-A421 is one of the most sought-after alto flutes in the world. It is characterized by an agile response and precise intonation, but its best feature is its warm, beautiful sound. Yamaha's unique expertise with the various alloys used in brass instruments led to the discovery that gold-brass (brass with a higher than usual copper content) is the perfect material for optimum tone, weight, and playability of an alto flute. The gold-brass gives a rich sound full of tonal colors, and the flute is much more comfortable to hold and play than traditional alto flutes, being considerably lighter. A model with a curved headjoint is also available by special order.