I get singers, occasionally, that want to record with Karaoke tracks.  I don't have any software that will change keys so they have to bring CD's with the tracks in the right key or in the case of one singer, he brought his laptop with his Karaoke software on it and we used that to generate the backup tracks in the right key (fed that to Sonar).
 
My question, is there a VST plug in for Sonar that will do this?  If not, what are recommendations for low $$ karaoke software that will do this.   I have a 15 day demo copy of PCDj Karaoke and it will do it, but its $100.  Surely there is something cheaper that can be used.
 
 

Have you tried the audio transpose feature ? 

Same as midi transpose (Process - Transpose), but you have to check the 'audio' box.

there is a free app on the net  called KEY CHANGER  http://download.cnet.com/...0-2139_4-10463799.html

I tried it and it works fairly well.  Just be careful on CNET.COM since they have lots of crapware links that you may not want.... search for the link to DL this.... or look on a different site.... I got this on one of my computers. I don't use it much because there are artifacts that I find objectionable. But it might work OK for what you need. 

I looked at Cnet a couple of days ago and you are right about the crapware.  They want you to install some type of Cnet download manager, etc.  I tried to go to the site for some of the listed programs and the links wound up back at Cnet.  This was the first Ive tried to download anything from Cnet for a year or two and it wasn't like that before. 

I'll check out the transpose feature.  I don't do anything with MIDI so I haven't used that function.

I tried the Transpose (several of its options) and its not what I want.  I tried it on a single instrument track and on a mixed down track.

I was linked to a plug in on the gearslutz forum, but the plug in is double the price of the PCDj karoke and my purpose is to find something cheaper as its only used infrequently.

Here is the plug in, which sounds great from the demo.  Elastique Pitch  http://www.zplane.de/products/plugins/elastique-pitch