Change Pitch
From Audacity Manual
- Accessed by:
Change Pitch works by applying an up or down percentage change to the existing pitch of a selection. As well as choosing the percent change directly you can define it as:
- a change from one pitch to another
- a change in semitones
- a change from one frequency to another.
If changing by pitch, modify the "To:" and optionally the "From:". If modifying by frequency, modify only the "to".
Change Pitch senses the first detectable pitch in a selection and sets "Pitch: From:" and "Frequency (Hz): from" accordingly. These two controls are not a detection of the "key" or "tonality" of music.
Pitch
If you know the key the original recording is in and the key you want to change it to, change both the Pitch "From:" and "To:" values. In the example above, the known key is being changed from F up to G.
Semitones (half-steps)
If you don't know the key the original recording is in but you know how many semitones it needs to be changed, enter that value here. For example you could duplicate a vocal track and then apply Change Pitch with a value of +7 semitones (a major fifth) to create a harmony vocal.
Frequency (Hz)
The "from" input box is preset to the first detectable pitch in the selection and cannot be edited. Detection of a steady pure tone will be quite accurate in which case you can change the "to" input box to the desired frequency for the tone.
Percent Change
If you would like to change the pitch by a given percent, enter a value in this input box or use the slider.
Limitations
Change Pitch is a time-stretching effect, because it defies the normal expectation that to lower the pitch of the audio it is necessary to reduce its speed (and thus its length) and vice-versa. As with any time-stretching effect, some audible distortions will be expected at more extreme settings.
Due to weaknesses in its algorithm, Change Pitch does not keep the length exactly as before. This makes Change Pitch unsuitable for changing the pitch of individual very short notes. To avoid this problem, you can use instead, setting initial and final pitch change to the same amount.
