Music tracks not playing

[junkdiver]

I had added an album to a media player with all tracks being able to play. After finding a conflict with the addition of tracks from another CD (multiple CDs in album) I had to make modifications to one directory.
The result was most tracks in the first album will play with sound the remainder show playing but with NO sound. I brought the same tracks up in VLC and they play the same way as in the media player. What prevents the files from playing with sound?

[Lotesdelere]

What kind of tracks ? Which format ?

[junkdiver]

The music files are WAV format.