Intro to Pitch Correction in Final Cut Pro for Mac
You can use the Pitch Correction effect to correct the pitch of incoming audio signals. Improper intonation is a common problem with vocal clips, for example. The sonic artifacts that can be introduced by the process are minimal and can barely be heard, as long as your corrections are moderate.
Pitch correction works by accelerating and slowing down the audio playback speed, ensuring that the input signal (sung vocal) always matches the correct note pitch. If you try to correct larger intervals, you can create special effects. Natural articulations of the performance, such as breath noises, are preserved. Any scale can be defined as a pitch reference (technically speaking, this is known as a pitch quantization grid), with improperly intonated notes corrected in accordance with this scale.
Note: Polyphonic recordings, such as recordings of choirs, and highly percussive signals with prominent noisy portions can’t be corrected to a specific pitch. Despite this, you may want to try the effect on drum signals.
Defining the quantization grid
Use the Pitch Correction effect’s Normal and Low buttons to determine the pitch range that you want to scan for notes that need correction. Normal is the default range and works for most audio material. Low should be used only for audio material that contains extremely low frequencies (below 100 Hz), which may result in inaccurate pitch detection. These parameters have no effect on the sound; they are simply optimized tracking options for the chosen target pitch range.
The Scale pop-up menu allows you to choose different pitch quantization grids. The scale that is set manually (with the keyboard graphic in the effect window) is called the User Scale. The default setting is the Chromatic scale. If you’re unsure of the intervals used in any given scale, choose it in the Scale menu and look at the keyboard graphic. You can alter any note in the chosen scale by clicking the keyboard keys. Any such adjustments overwrite the existing user scale settings.
There is only one user scale per project. You can, however, create multiple user scales and save them as Pitch Correction effect settings files.
Tip: The drone scale uses a fifth as a quantization grid, and the single scale defines a single note. Neither of these scales is meant to result in realistic singing voices, so if you’re after interesting effects, you should give them both a try.
Use the Root pop-up menu to choose the root note of the scale. (If you chose User Scale or Chromatic in the Scale pop-up menu, the Root pop-up menu is nonfunctional.) You may freely transpose the major and minor scales, and scales named after chords.
Excluding notes from Pitch Correction
You can use the Pitch Correction effect’s onscreen keyboard to exclude notes from the pitch quantization grid. When you first open the effect, all notes of the chromatic scale are selected. This means that every incoming note will be altered to fit the next semitone step of the chromatic scale. If the intonation of the singer is poor, this might lead to notes being incorrectly identified and corrected to an unwanted pitch. For example, the singer may have intended to sing an E, but the note is actually closer to a D#. If you don’t want the D# in the song, the D# key can be disabled on the keyboard. Because the original pitch was sung closer to an E than a D, it will be corrected to an E.
Note: The settings are valid for all octave ranges. Individual settings for different octaves aren’t provided.
You can use the small bypass (byp) buttons above the green (black) and below the blue (white) keys to exclude notes from correction. This is useful for blue notes. Blue notes are notes that slide between pitches, making the major and minor status of the keys difficult to identify. For example, one of the major differences between C minor and C major is the Eb (E flat) and Bb (B flat), instead of the E and B. Blues singers glide between these notes, creating an uncertainty or tension between the scales. Using the bypass buttons, you can exclude particular keys from changes, leaving them as they were.
If you enable the Bypass All button, the input signal is passed through unprocessed and uncorrected. This is useful for spot corrections to pitch through use of automation. Bypass All is optimized for seamless bypass enabling or disabling in all situations.
Tip: It’s often best to correct only the notes with the most harmonic gravity. For example, choose “sus4” from the Scale pop-up menu, and set the Root note to match the project key. This limits correction to the root note, the fourth, and the fifth of the key scale. Activate the bypass buttons for all other notes and only the most important and sensitive notes are corrected, while all other singing remains untouched.
Automating Pitch Correction
The Pitch Correction effect can be fully automated. This means that you can automate the Scale and Root parameters to follow harmonies in the project. Depending on the accuracy of the original intonation, setting the appropriate key (Scale parameter) may suffice. Less precise intonations may need more significant changes to the Scale and Root parameters.
For more information on automating Pitch Correction, open Final Cut Pro and choose Help > Final Cut Pro Help.