Since ATRAC3 is a format for console audio, I converted the music files from that format to MP3 so you can throw this rip onto your iOS or Android device and rock out listening to the game's BGM. The filenames haven't be edited, they are what was outputted by my ripping tool. A good chunk of the files are actually ambiance (field records, likely) of downtown Akiba from what I can hear.
The music from Akiba's Trip 2/Undead & Undressed is copyrighted by Acquire Corporation in Japan and licensed to XSEED Games/Marvelous in the USA. However, I personally believe that you aren't going to get into trouble listening to a console game's background music. YMMV.