Charge for membership or posting and you will kill it.
Does the USA have anything like the EFDSS? Has anyone tried the EEC? They are very keen on EEC member state cultural traditions, but I doubt if there is enough European content here. Would ASCAP or BMI like to improve their image and sponsor? What about the American equivalent to the BPI? Try the Musicians' union - over in the USA perhaps Local 47.
This discussion group works very well. Perhaps a software company would like a licence of the software?