What are the timbral (sound quality) differences between nickel, silver and gold flutes, and what is it in these materials that produce the different sound qualities? I'm a string player, so I only know that these different materials exist, but I'm unclear about what they do. Also, are there other notable western flute materials?
The general opinion (highly subjective) among flute players is that denser precious metals produce an better sound. Gold is claimed to produce a warmer, darker, more complex sound, silver is claimed to be brighter and have more projection. Professional players nearly always play at least a full silver flute if not a gold one, although there are some exceptions.
One factor that must be considered is that much more care is taken in the construction of flutes using expensive materials so they will be better instruments. You'll never find a gold flute made in a factory.
Nickel, silver and gold or alloys/combinations of these are the most popular materials. Often a silver flute is upgraded by using a gold head joint. A silver head joint might have a gold 'riser' (the piece between the body of the head joint and the lip plate) or a gold lip plate. A nickel-silver flute can be upgraded by using a full silver head joint.
Sometimes other material are used:
- Platinum is extremely expensive but flutes made from it are said to be even better than gold flutes.
- Wood, most commonly African blackwood (grenadilla or Dalbergia melanoxylon) is still preferred by a few players.
- Carbon fiber
- Plastic. There are cheap, almost unplayable plastic flutes available
- Brass (silver-plated)
The reason why noble metal produce better flutes is unclear, the density of the material and its heat conductivity might be the reasons. There are scientific studies with inconclusive results