Such devices exist on their own which record about 10-20 seconds on an internal memory, and then somehow double all the digital information so that it can be player at 1/2 speed but remains on pitch. This is a real help to musicians who play by ear but I suspect a special device for this purpose is now archaic.
I have used tape players which lower the pitch by one octave, but I'm assuming there is better technology today.
Any idea what such technology is called and if there is software which accomplishes this?
www.soundjam.com and www.macast.com
These are software products that allow you to play music (mp3 and other formats) on a MAC. You should look to see if either product can change speed without changing pitch. This is probably done via a "plug-in".
Kris Jensen writes: