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.
Please refer to below for specs
The headjoint is designed to easily catch the air stream delivering excellent response. Easy to tongue with good, even resonance over the entire range it is well suited for use in orchestras. (Photo: straight head joint for YFL-A421)
Key shapes are designed to provide a natural position that fits the fingers for greater playability.