A control ( usually a slider ) on a DJ's turntable that allows the speed of rotation to be varied from the base speed of 33 or 45 rpm. This allows the DJ to beatmatch when mixing two tracks with different bpm rates.

Usually the pitch control allows an adjustment of up to +/- 8%. So If you have a track that normally plays at 120 bpm you can speed it up to 129.6 bpm or slow it down to 110.4 bpm. It is often possible to adjust the pitch control so that it can provide a greater adjustment (for example on a SL 1200 deck the range can be increased to +/- 16%), however this is usually inadvisable since it necessarily makes the pitch control more sensitive and harder to make fine adjustments with. Also, if you get a gig the decks at the venue will almost certainly have +/- 8% pitch controls.

Most pitch controls also have a crystal lock switch which will bypass the pitch control completely and force the turntable to spin at the base speed. This is useful if you are trying to synchronise the pitch controls of two decks, or work out the bpm of a track.