Facility on some sound playback devices for changing the speed of playback, and thus the pitch or frequency of the sound, to match an existing sound, or to fit a particular timeslot. Some Professional CD players have tempo controls which speed up the playback, and then compensate for the resulting increase in frequency using a pitch change. This results in the ability to match the beat of a CD in a disco situation, without the "Pinky and Perky" effect.