Sega tells Joystiq it made every effort to pursue and re-license all the music, but cost and even the availability of certain music publishers became an impediment. In the end, Jet Set Radio keeps its original music (composed by Hideki Naganuma), and several fan favorites like "Magical Girl" (Guitar Vader) and "Funky Radio" (B.B. Rights). We'll probably survive without Rob Zombie.
Though the NTSC- and PAL-specific tracks haven't made the cut, the levels developed for those versions (including Grind Square) will be included with this summer's HD port. The preservation may not be flawless, but the presentation nearly is -- Jet Set Radio's bold, cartoonish aesthetic benefits immensely from the higher resolution, 16:9 display and 60 frames-per-second output. Oh, and there's one more thing you didn't have before: a second analogue stick to steer the camera!