I have an MP3 file of a specific song where the instruments are not tuned to 440 Hz. When you play along to this song with a 440-Hz-tuned instrument your playing will sound out of tune.

There is a way to get the tuning of the song using the program Sonic Visualizer (Analysis -> Tuning). For my song I got 448 Hz for example.

Now I want to pitch shift this song so that it sounds in tune. I know that for example Audacity should be capable of this, but which function do I have to use with which values, knowing only the two tunings?

  • Are you content with slowing the resulting recording down in the process, or must the result be in the same tempo as the original? – Dekkadeci Jun 23 at 12:28
  • I can't speak to the method for pitch-shifting in Audacity, but I will say I'd rely on something other than software to determine the recorded pitch. 448 Hz certainly isn't impossible, but I'm skeptical. What is the piece in question, and the recording? When a recording uses a pitch other than 440, it's usually to replicate historical conventions, and 90% of the time this means a lower pitch rather than a higher (there are a few exceptions especially in some very diligent recordings of some German sacred music),... -> – Andy Bonner Jun 23 at 12:33
  • -> ... and 90% of the "low-pitch" recordings use 415 Hz rather than any hyper-historical choice. If you're dealing with a very old recording, it's also possible that the pitch is higher than what intended due to problems with recording or playback. I'd recommend simply looking at the score to see the intended pitches, and then adjusting by ear (either using trial and error with the pitch correction until you "hit" 440, or using a tuner or synthesizer that can be calibrated to try to adjust a generated tone until it seems to match. – Andy Bonner Jun 23 at 12:37
  • @AndyBonner Recordings are often speeded up or down during mastering, they even used to do this in the days of analog recording. – PiedPiper Jun 23 at 12:42
  • @PiedPiper True, maybe I shouldn't say "problems" with recording, though some might certainly argue that a rogue performer, conductor, or producer altering the pitch and tempo merely because it "felt slow" is a problem, especially in the kind of chip-on-the-shoulder world that is proud of either their modern 441 or their 438 that they based on the latest measurements of the Nuremberg organ, combined with historical weather forecasts to best extrapolate the sounding pitch. ;) – Andy Bonner Jun 23 at 12:59

Select the bits of your track you're interested in (e.g. with Ctrl+A for the entire track) and apply Effects-> Change Pitch. Just enter the two frequencies under 'Frequency', and it calculates the correct percentages. 'Change Pitch' will preserve the original tempo, as opposed to 'Change Speed'. enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.