TweelX is a real and just launched stock exchange to trade music rights. Real stock exchange means a publicly registered marketplace for stocks with stocks being shares of particular songs. This becomes possible by a lately change of the related US regulations according to the press release about the launch of the service.
This is how TweelX works: Musicians or song writers do submit a music piece. By doing so others are enabled to invest in this piece of music by buying stocks. There are just five stocks available to each music piece, which each represents five percent of revenues generated by the piece. The revenues comprise sales as well as other revenues generated e.g. by licensing. The stocks may be traded on the platform, which in addition gives to investors the option to generate profit by selling the stocks. The company by the way is located in the center of country music in Nashville, Tennessee.