No, the PSR-I455 can't play MP3 files, and there's currently no way to convert MP3 files-- or any other audio files-- to MIDI. There might be some programs that try to convert MP3 files to MIDI, but the results are usually poor at best due to the complexities of sound. In particular, there are the problems of the various harmonics that make up a given instrument's timbre and whether to interpret them as one note or many notes; trying to separate multiple instrument timbres from each other; and trying to separate multiple notes played by a given instrument from each other. It may eventually be possible to convert an MP3 file to MIDI, but even then the results probably won't be guaranteed and will need to be reviewed and corrected by a human being-- similar to scanning a page of print and using an OCR program to convert the image into text characters, then having to review the resulting text carefully to find and correct any errors that the OCR program may have made.