Karaoke Japanese Mp3-G is the newest format for karaoke music that is becoming very popular everywhere, not just in Japan. Mp3-G is basically the combination of 2 files stored on a disc, an Mp3 file that holds the karaoke music and a graphics file to view the lyrics of the song. Karaoke Japanese Mp3-G uses the great compression of an Mp3 audio file and graphics file which results in what you see on the screen.
This format has the advantage of having a lot more songs on one disc compared to a CD-G since Mp3 files are a lot smaller than CD-G files and for this reason Karaoke Japanese Mp3-G files are becoming very popular.
Right now this format will only play on certain CD / Mp3 Players. CD-G is still more standard over Karaoke Japanese Mp3-G and CD-G stands for Compact Disc + Graphics similar to Mp3-G. This format is the standard for most English karaoke discs. These discs can either be played on a karaoke machine that supports CD-G or on a regular player that can play CDs.