This is an area where Roland's R-Mix technology REALLY shines. It is the best tool I have found for learning new parts. The BAD news is that R-Mix isn't available in Sonar X1. The GOOD news is that it is an announced feature in the upcoming X2 version. AND it is currently available standalone.
Not only can you change speed but you can...
- change pitch
- isolate (to a very large degree) one instrument in the mix.
- move an instrument in the stereo field.
I recently used the tool for a friend who was trying to learn a harmony part to a song but was having trouble hearing it in the mix. Just using a commercial CD mix it was very quick and easy to greatly enhance the harmony part, reduce the level of some instruments and the lead vocal, move it to be panned center - and then transposed the entire arrangement to the key she would be singing in.
Don