HoRNet Plug-Ins has released a software application that will detect the song key for every mp3 in your library.

Key detector is a software designed to help DJs to do harmonic mixing, in the words of wikipedia:

The primary goal of harmonic mixing is to create a smooth transition between songs. Songs in the same key do not generate a dissonant tone when mixed. This technique enables DJs to create a harmonious and consonant mashup with any music genre.

Key Detector is able to analyze a single mp3 or a folder (and it’s sub-folders) and scan all the mp3s contained. The software is powered by Opens internal link in current windowHoRNet SongKey which empowers artificial intelligence algorithms to detect the key of the song, three different keys are identified and ranked in order from the most probable to the least, the software is then able to write the identified key to the ID3 tags of the mp3.

Key Detector for Windows and is available for purchase for 19.90 EUR.

More information: HoRNet Plug-Ins