How different in terms of audio/music are MSX2 games played on MSX2+ (i.e. Space Manbow, Quarth, and Metal Gear 2)? This is about games that say MSX2/MSX2+ on the packaging.
Specifically for those games, in terms of audio/music, no different. In terms of visuals, only Space Manbow has a visual enhancement where the left and right edge of the screen are masked off cleanly into the borders instead of flipping.