MP3 Key Changer is an application primarily used for changing the key of an audio track. This allows the user to tune the song according to a preferred key, which is normally within the user’s vocal range. To use the program, the user first loads the audio track using the file browser. It can also be done through the application's drag-and-drop feature. The program converts or modifies one track at a time, which makes it efficient as the minimal resources used by the application are focused on that track.
When editing the key of a song, the user can use the built-in player to test how the output file sounds. If the expected output file is not in the key the user desires, there is the option to revert and continue with the editing process. A slider is used to navigate through the audio track. While the audio track is playing, the player can either pause it to fine-tune some properties, like the tempo of the song.
Once the user has finished editing the audio track, the conversion process can begin. Upon the conclusion of the converting procedure, the output file is then saved in the user-selected output folder or other location.