 Among various new ideas, Grainger introduced his so-called "free-music" theories. He believed that conformity with the traditional rules of set scales, rhythms and harmonic procedures amounted to "absurd goose-stepping", from which music should be set free. He demonstrated two experimental compositions of free music, performed initially by a string quartet and later by the use of electronic theremins. He believed that ideally, free music required non-human performance, and spent much of his later life developing machines to fulfil this vision.
