Karlheinz Brandenburg, credited with at least jointly “inventing” MP3, has joined with a German development bank to invest in DJTunes, a European music download site offering house, techno, trance and electro tracks in that very file format. “With our renowned partners, we can target new products and markets and thus significantly increase our growth rate,” CEO Timo Becker said (release).

DJTunes targets DJs, club-goers and labels and claims over 300,000 tracks, all in the DRM-free format that is beloved of DJs for its lack of copyright locks - if not exactly for its high fidelity. The site lets users upload and sell their tracks and mixes, and will use the funds in part to branch out by launching a hip-hop site next year. The investment is made along with Beteiligungsmanagement Thüringen (BM|T) though the size is undisclosed; DJTunes also got seed funds in 2006.

Professor Dr Brandenburg’s 1989 dissertation was the basis of MPEG-1 Layer 3 audio compression and he went on to work with AT&T (NYSE: T) Bell Labs but now directs the Fraunhofer Institute for Digital Media Technology, which now licenses the MP3 format. DJTunes has set up an office alongside the institute in Ilmenau, Germany. Brandenburg is one of five folks listed on the MP3 patent.