I use Noteworthy, and within that you can define the tempo. It doesn't change the pitch. An evaluation copy is free, but has a few restrictions such as the number of saves you can make, and you can't print (although you can cut & paste into Word). The full copy is inexpensive for what it does. I think it's really useful for what you're trying to do, and you could even use it to help you learn to read the dots. Good luck.