Download Zedge, or use the music or audio files stored on your SD card by using a MP3 ringtone editor app to shorten the length of the song or play parts only you want.
Go back to flash, and do a recovery, if you had backed up your previous files reflash it to them and you should be fine, if that doesn't work, whatever he used to flash it or however he did it he managed to forget an important file.