Fig 1. Simple frequency relationships between notes
The idea was to restore the musical scale to its former whole-number simplicity, and abandon Equal Temperament as the limitation of fixed-pitch instruments, instead modulating the tuning, using a frequency from the playing chord as the input for the next note, as can be seen in Figure 1.
Mechanical system from (Rosberger, 1970)
To accomplish his designs, Rosberger envisioned a mechanical system of motors and alternators, connected by a shaft, using a memory drum to store frequency ratio information, and employing magnetic tape as an eventual output in recording. A disadvantage of this system was that the performer was expected to preprogram the intended ratio combinations using punched tape. While this opens up an extended choice of frequency relationships such as the false fifth or diminished third, it required forethought, and couldn't make on-the-fly adjustments. To truly implement a Pythagorean scale, the system would have had to run the same signal through both 3:2 and 2:1 transforms as many times as necessary - harder to achieve, but perhaps saving space.
The Wandering Tonic
Notwithstanding the kerfuffle over the system's mechanical realisation, 'Total Consonance' allowed a way to modulate to far-foreign keys, while still maintaining sweetness in all intervals, and avoiding the fabled wolf notes. It did, however, present a different problem. Take a look at Figure 3, which is an elaboration of Figure 1.
As can be seen, with the specific application of frequency ratios used, the note frequencies are subject to change.
Rosberger wasn't much perturbed by the wandering tonic effect:
"That the first frequency should be absolute should not concern us as much as its relation in conjoining it with succeeding frequencies"
The strength of the effect on the listener and the parameters that influence it are worth studying, in order to arrive at a model to potentially assess, then reduce or negate potential effects upon the listener.
In the event, Rosberger's ideas were overshadowed by the end of the decade by the uptake of microprocessors in musical synthesis. The idea of total consonance still continues, aided by digital technology and music production software; from motor to mouse, things are a lot easier nowadays in terms of accessibility and operation, and the book remains an unfortunate victim of timing.