How do we make musical sounds? To make a sound, we need
something that vibrates. If we want to make musical notes you
usually need the vibration to have an almost constant frequency:
that means stable pitch. We also want a frequency that can be
easily controlled by the player. In electronic instruments this
is done with electric circuits or with clocks and memories. In
non-electronic instruments, the stable, controlled vibration is
produced by a standing wave. Here we discuss the way strings
work. This also a useful introduction for studying wind
instruments, because vibrating strings are easier to visualise
than the vibration of the air in wind instruments. Both are less
complicated than the vibrations of the bars and skins of the
percussion family. For the physics of standing waves, there is a
multimedia tutorial. The strings in the violin, piano and so on
are stretched tightly and vibrate so fast that it is impossible
to see what is going on. If you can find a long spring (a toy
known as a 'slinky' works w