To get assistance for tuning the bottles, it is best to use a tone generator to get an idea of the sound you are aiming for when you strike the bottles. These are available in many forms; one good website that does this is http://plasticity.szynalski.com/tone-generator.htm, which allows you to select any note and play a sample of it. Audacity (http://audacity.sourceforge.net/) is an example of a piece of desktop software that does a similar thing. There are also many smartphone applications that have similar features.

The first step to tune a set of bottles is to sort the bottles into groups of unique combinations of shapes and sizes. The combination of these two properties will define the pitch of the sound a bottle without any liquid makes when it is struck (the frequency of which is known as the bottle's natural frequency, that is, the frequency at which it will oscillate when not exposed to external dampening). We will then use the bottles with the lowest pitch for the lower-pitched...