Reaper is a powerful digital audio workstation (DAW) for Windows and Mac operating systems. It can be used to record, edit, mix and export audio to a variety of formats. One of the effects that you can apply to a track is named Reapitch. Reapitch is a plug-in that will alter the pitch of your audio track while providing you with several parameters to set so that you have the greatest control over your pitch shift.
Open Reaper. Record a new track or insert a previously recorded audio track by selecting "File" then "Import,"
Click the "fx" icon on your track. This will be a small gray box located to the left of the audio track. This will open the "Effects" window.
Select "Cockos" from the list of effects on the left side of the window. In the window on the right select "Reapitch," This will open the Reapitch effects window.
Select the "Enabled" check box if it is not already checked. Use the "shift" control to shift the pitch of your audio track. You may shift in semitones or cents. One semitone is equivalent to a musical half-step. One hundred cents equals one semitone and should be used for fine control over your pitch shift.
Use the "Wet" and "Dry" sliders to indicate how much of the effect you want to be mixed in. The "Wet" fader controls that pitch shifted signal, while the "Dry" fader controls the original signal. If you would like to shift the pitch of the audio track completely, set the Wet slider to "0" and the Dry slider to "100."