Brian,
It would seem that changing Tempo with Audacity is not all that is seems, as when you do this, "wow" and "flutter" is introduced resulting in distortion. As confirmed by the section where he slowed it down to just under half speed. Yikes!
Here is another tutorial illustrating this, and even when the change of tempo is only 4% it makes it unacceptable as a piece of recorded music. Click on the below for the video.
You may wish to do a 'right-click' and open the link up in a New Tab.Of course this video has been made by a company promoting their own product, Song Surgeon, which costs about $100 (£74).
Out of interest, I have tried changing the Tempo using Audacity with one or two pieces I have played .. not very successfully. In the end, as I had the music recorded on floppy disk anyway, I was able to re-record the pieces directly from the AR, and could
slow down/
speed up the tempo of the piece directly off the floppy. I have the option of 'playing' the piece from the floppy at between 50% to 200% (ie. half speed to double the speed). This works with
no change of pitch, and
no distortion.
Also, when playing back somebody else's floppy track in my AR I can get the Left Hand Chords showing on the AR's screen, so often slow the music down to 50% so I have time to write the chords down!
Hugh