Open the MP3 in Sony Acid Pro. This program will allows you to change the pitch or key of a song without altering the length or speed.
Click on the waveform (the displayed visual interpretation of your audio file) and press the plus and minus keys on your keyboard's number pad to alter the pitch.
Render the song as an MP3 file, using the same bit rate as the original file once the song is at the desired pitch.
Use Virtual DJ to change the pitch of an MP3 during a live event or performance.
Drag your MP3 to one of Virtual DJ's onscreen turntables to load it into the program.
Manually alter the speed of the song by spinning the turntable, pressing and holding the pitch buttons to the lower left of the turntable or by moving the pitch lever up and down. Increasing the speed of the MP3 automatically increases the pitch and key.
Import your MP3 into FL Studio and use it as part of a sampling project or song.
Load the song into one of the tracks in FL Studio's pattern sequencer and access a virtual keyboard to control it by clicking on the keyboard button in the upper left corner of the sequencer.
Trigger the sample using the program's virtual keyboard to alter the pitch every time you press a different key. This will change the speed of the song as well as the key.