The double siren, based on Helmholtz’ double-siren, wich he used for measurement purposes, has got various just intervals. The intervals that we will be able to use for the first compositions are gathered in a scheme:
The green column represents series of holes resulting in tones of different pitch. These series of holes will be available for the first compositions. The names of familiar intervals are standing above the musical intervals. source: http://nl.wikipedia.org/wiki/Lijst_van_intervallen