Changing Key (Is this the same as a pitch change?)

Windows 8.1 Audacity 3.0.2

Or, better, if I want to transpose an mp3 audio file from the Key of C to the Key of F would I use the ‘pitch change’ feature?

Assuming this is correct, I can only assume there is more to it than simply capturing the entire piece, clicking on Pitch Change and follow the steps.
My real question is I did just that and I was not unhappy with the result. But then I tried to transpose from C to F# I did not like the result.

The original pieces is a orchestra piece with basses, violins, drums, horns, etc. When I transposed to F I feel most of this detail remained only in a different key. But when I went to F# the sound was almost mechanical and differently not like an orchestra.

I have had very little experience with Audacity so I am very much a newbie.

Thanks for any help you can provide as I will probably want to lean on Audacity to make key changes to mp3 files.

[u]Sliding Stretch[/u] uses a higher quality algorithm (and you don’t have to “slide” or “stretch”).

…There is another problem in-that when an instrument plays a higher or lower note, other characteristics besides pitch change or don’t change. When you pitch-shift everything shifts the same so the farther you go the more unnatural it gets.

if I want to transpose an mp3 audio file

As you may know, MP3 is lossy compression. When you open a compressed file in Audacity (or any “regular” audio editor*) it gets decompressed. If you then re-export as MP3 you are going through another generation of lossy compression, and some damage does accumulate. You may not notice any quality loss but it’s something you should be aware of.

Ideally, if you want MP3 you’d start with a lossless original and compress ONCE to MP3. Otherwise try to minimize the number of times it’s compressed.

Or, if you don’t need an MP3 you can save it as WAV (or FLAC). The “damage” is done during compression (not during decompression) so no additional damage will be done when it’s decompressed, and it would be decompressed when played anyway.


  • There are special-purpose MP3 editors that don’t decompress/re-compress the file. But they can only do simple editing, so no pitch shifting or EQ or “special effects”.

If you are making a small pitch change (which you are not at the moment) it’s often better to use the Change Speed effect which changes the speed and pitch together. (A small tempo change is often not noticeable.) This is a much simpler algorithm (essentially the same as changing the speed of a tape recorder or record player) so it’s less prone to side-effects.

In recent versions of Audacity, “Change Pitch” and “Change Tempo” effects provide an option to use the same algorithm as “Sliding Stretch” uses.
To enable the higher quality algorithm, enable the option: “Use high quality stretching (slow)”