This is the title of a French book published in the late 70's and I have translated the back cover text which is think in sync with CBG making philosophy. So here it is:

"We propose building instruments - playing them, inventing new ones. Not only because these instruments are inexpensive, but also because of this...

Not only because these instruments allow, through their manufacture, a demystifying research-discovery activity, associated with the pleasure of creating the object... but also because of this...

Not only because most of these instruments can be used almost immediately, with no need for prior learning, and thus immediately encourage "equal" play situations... but also because of this...

Not only because these instruments can in some cases be "springboards" for learning and using other, more complex instruments (orchestral instruments), but also because of this...

Not only because, on the contrary, these instruments can "short-circuit" the use of more complex and typical instruments (orchestral instruments), but also because of this...

Not only because these instruments can also be used to educate the listener, leading, as and when required, to theoretical acquisitions (solfeggio, exploration of different modes, formal analysis, etc.), but also because of this...

Not only because these instruments make it easier for a collective to find itself in forms of playing that are different from the usual ones, more centered on the group and its history, by reappropriating the material of expression of a collective that sound can be, but also because of this...

Not only because these instruments, by offering modestly to people the chance to recreate and reinvent to reinvent a "lutherie" that fits to who they are, to avoid the fixism of today's lutherie, but also because of this...

Not only because these instruments very often encourage the creation of acts tending to reduce the "eternal" divisions between "creators-consumers", "work-leisure", and, to a lesser extent, on the occasion of construction, that between "intellectual-artistic worker, and manual worker", in any case help to re-situate them differently in a non-hierarchical way, but also because of this..."