Pitch is simpl;y defined as varying the frequency of any tone.In the world of muscial
compostion, the standard for the note "A" is a frequency of 440 Hertz (Hz). If we were
to record the note "A" on an analog tape machine with a pitch controller (aka VSO or
"variable speed oscillator") and decrease the pitch of "A" a semitone, it would change
to A flat (Ab). If we were to increase the pitch by one semitone, the note would change
from A to A sharp (A#).  As we change the pitch up or down, the tempo of the note or
notes change as well.

Note: there are 12 semitones in one octave. This is the standard to chart notes and
chords in music. Even though this is an audio recording course, a basic understanding
of this concept of pitch is helpful, as the manipulation of pitches can be of use to the producer.

When I first began recording over twenty years ago, I began experimenting with the pitch control on what was the first commercially available cassette 4 track machine, the Tascam 144. It struck me that musicians on commercial recordings sounded different from their live perfomamces. I then began raising the pitch of my recordings  up tp one semitone (for example, from an F# to G) and noting similarities in what I was hearing on commercial recordings, especially inthe sounds of voices and certain instruments such as drums.

Here is an excerpt from the British recording business magazine SOUND ON SOUND, on the
subject of how pitch is used in by the recording industry in the mastering stage of the recording process.

"The other way of speeding up a track which used to be used on a very regular basis was to slow down the
mastering tape machine by a factor of 8.5% at the final mix stage. When played back at normal speed, the
finished master would be slightly over a semitone higher in pitch. The reason for this was that it made the
playing sound a bit tighter, particularly the drums, and gave the overall sound a bit of a toppy edge.
On the downside, it made working out songs from the record difficult, because they were often
slightly out of tune."  EMI Mastering of recordings by The Beatles

One semitone = approx. 4.5% change. I like to master in exact semitones and not "in the cracks."

Perhaps there have been times where you have been listening to a commercially produced CD and
you tried to follow along on some instrument you were playing. You may have experienced difficulty
following because chord changes and note riffs might have whizzed by in a near blur, leaving you aghast at
how fast a particular passage might have been playing. What you are noticing is anywhere up to a semitone change in
pitch from the original recording, which also increased the tempo of the song if it was an analog recording. You may have also noted diiferences in how an singer sounds live as opposed to how they are heard on record as well. Even so-called
"live" albums can be pitch adjusted (and heavily edited and overdubbed as well in many circumstances).

There are devices called pitch shifters which change pitch but not tempo. Usually these are digital based and not analog.

Analog tape in the pre-digital area changed the speed of the tape approx. 4.5% to match the 1 semitone.

Refer to the book "Recording the Beatles" and an entire section is devoted to which songs the band employed varipseed effects to change the pitches of vocals or instruments.

You can take any song that's been digitized and open it up in any audio editing program like Audacity or Adobe Audition. The 1 semitone mark may not be EXACTLY the original pitch,
as their are sub-increments of semitones called "cents." There are 100 cents in 1 semitone. Some programs allow adjustments of 10 cent increments between semitones. Some bands adjust the pitch of their final product even before the mastering stage. The Beatles did this quite a bit. 1  2  3

Here's a great example of pitch differences ... listen to the group Wilson Phillips performing the song "God Only Knows" live on a TV show. Note the difference in pitch compared to the studio version. The TV performance is -1 semitone lower than the studio version. I've also taken the TV studio performance and raised it +1 semitone. Note how it matches the studio version exactly.

TV show performance (natural pitch, no pitch adjustment)

Studio version

TV show (+1 semitone)


Three different mixes of Rolling Stones' "Jumping Jack Flash." 


Two different mixes of The Beatles' "Across the Universe."   1    2

"She's Leaving Home"   Stereo version (-1 semitone)    Mono version (natural pitch)