As @Atlas007 pointed out, that's a job for Varispeed.
Control-click an empty spot in the Control bar and choose Customize Control Bar and Display,
In the LCD column, click the pop-up menu, and choose Custom,
Below the pop-up menu, select the Varispeed checkbox,
In the LCD display, click 'Speed Only' and choose Varispeed (Speed and Pitch),
Click the % unit and choose Detune (Semitone.Cents),
Adjust the number of semitones.