You want to practise for your exam. You take out the CD from the envelope at the back of the book, but horror of horrors, it goes at the speed of light, and you can't keep up.

For me, the problem of changing the speed of a backing track arose during online singing lessons, when a student needed a backing track for Die Forelle in D flat major. The one I had was way too fast. What to do?

Is there a software solution?

You could download Amazing Slow Downer - it promises to be able to slow down the track without changing the pitch. I have never used it, but if it works, why not?

I find that the audio software I use (Amadeus), which is excellent in many respects, does not make a good job of slowing down the track. At about 90%, the piano part begins to sound distorted, and sopranos sound very fruity - more like high altos.

However, there is an online solution to this problem, that is free, and that is YouTube. (1) - see note

YouTube can slow down soundtracks without changing the pitch

YouTube has the ability to play videos at different speeds really well. Here's how:

(1) Click on the cogwheel in the bottom right of the video in YouTube

(2) Select one of the presets, or choose 'custom'

(3) Move the slider to change the speed in increments of 1%

You can also upload

Even better, you can upload your own tracks to YouTube. The instructions on how to do that are here:

​ https://support.google.com/youtube/answer/57407

There are two further steps - you can't upload audio files. They have to be in a video format. There is a list here:

​ https://support.google.com/youtube/troubleshooter/2888402

Converting audio files to YouTube-friendly video

There are plentiful supplies of video conversion software that will do the job for free, and convert an mp3 files to mp4.

Zamzar will convert small files for free:

​ https://www.zamzar.com/

And Online Converter will convert bigger files (I haven't done a comparison, but it seems to result in much larger mp4 files):

​ https://www.onlineconverter.com/audio-to-video

Private vs Unlisted

Finally, I would change the privacy settings on the uploaded file (or even before I upload it). This article explains the difference between public, private and unlisted:

​ https://support.google.com/youtube/answer/157177

Conclusion

Is this a bit of work? Yes. But it is free.

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(1) Mark Swingler wrote to me to say that there are many online solutions to speeding up and slowing down tracks, including Windows Media Player and QuickTime.

https://www.timeatlas.com/speed-up-videos/