This should be pretty easy to do.
It will help if the vocal track:
1. is a set number of bars long (e.g. you bounced a stem exactly 24 bars long)
2. keeps the same tempo all the way through.
Then all you need to do is import the vocal track into the new project, hold down option and drag the right hand edge of the file to the left until it is exactly the same number of bars long as before.
so using the example above, when you import the 24 bar vocal track into the faster project it will end up [i]longer[/i] than 24 bars in the new tempo. Hold option + drag the edge back to the [i]end[/i] of bar 24 (aka the start of bar 25) and it should end up in pretty good sync.
This will still work fine if the vocal track is in smaller pieces.
There are other methods out there, which will help if:
- the vocal changed tempo during the ballad, or
- the vocal is following a groove that doesn't naturally suit the new dance beat you're putting it to.
Get back in touch if it doesn't work for you, and we can go over some other methods. But option + drag has always been the easiest way for me.
Hope that helps!