Dual Player

Dual Player is a tool you can use to compare 2 sound files in order to find differences in them. If your files are in different formats (like MP3 and WAVE) or differ in length then you can't use hashes (CRC-32, MD-5) to compare them. But you can use this tool and check in a few seconds whether your music files are different or not. Then yon can decide which file to keep and which to delete.