MP3 Key Changer is an application which helps users to edit, play and save MP3 tracks. This program is very simple and it has only two main functions. The first one is the ability to change temp of the song, this function will be of help if you want to play a song faster or slower. The second function allows users to transpose the song up or down to 6 semitones. When you load a track into this program it automatically detects the tempo of this track. Due to the simplicity of the program it is very easy to understand how it works. The interface is very simple too; there is only one window where all tools and functions are located. Within the options window you can select the audio-out and MP3 parameters, such as bit rate and frequency. There is also a possibility to select between 128kb/s, 160kb/s, 192kb/s, 256kb/s and 320kb/s. The application supports only MP3 and WAV formats. Evaluation version has limitations; all functions are available but program plays only one third part of the song. Tracks edited with the help of the trial version can be saved only three times.