Duplicate cleaner is a great tool in finding mp3 duplicate files, – and more… Photos, Word documents, PowerPoint presentations, videos…
Features: Find Duplicate Files by content; Fast Scanning and accurate duplicate comparison; Deep scans music – locate duplicate mp3, wma, flac, ape, ogg formats; Flexible search parameters; Intelligent Selection Assistant; Search home or networked drives; Search multiple locations; Export / Import results in CSV format; View Path, Size and Date of files; Large, resizable list window; Image preview window; Delete duplicate files to the Recycle bin; Move duplicate files to a new location; Turn duplicate files into hard links (NTFS file systems only); Protection for Windows and system files.
The Selection Assistant is a great option; when you need to decide what to keep among all those duplicates, it lets you choose by bit rate, size of file, duration, etc.
To search your audio files by title, etc they need to be tagged. Normally they are, but if not, you can tag them automatically with mp3tag. You may also want to know how to remove duplicate entries from your Winamp playlists.