Noel Borthwick [Cakewalk]
Tempo maps do not affect playback of normal audio clips as long as they are not groove clips or audiosnapped clips with follow tempo enabled. The timeline scaling however will change to adapt to the tempo map. You can verify this by drawing  in a tempo map in a project without any loops or groove clips. The audio clips rendering will not be affected.

Noel,
 
Thanks, that's what I expected and hoped.
 
However, when I follow these steps:
 
1. Ctrl-A and Bounce to Clips an all audio project.
2. Select one clip and drag to the timeline
 
the result is a Tempo Map matching the clip in Step 2. However, the other tracks, previously in good timing, are now out of time.
 
Any thoughts as to why this happens and how to avoid it?
 
Admittedly, this is a project I've been working on for a long time, through several versions of SONAR. Starting fresh with a new project, I haven't seen this happen in my experiments.

There does seem to be a change to the start time of an audio clip when adding a tempo map, if the clip is set to musical time instead of absolute time.  When I drag and drop a second audio file into a new track, it comes in as using a musical time base which then creating a tempo map from the first audio track in the project changes the timing.  But if I set the second audio clip to absolute time, the tempo map doesn't alter the timing.  Audio clips need to start at a non-0 time for this to show up I think.  A fully bounced track it shouldn't matter, but any floating clips that are using a musical time base seem to change with the tempo map changing.  Could also have something to do with some settings I've enabled and didn't realize it as well perhaps.

On a Acid Loop style project (with clips of audio all over the tracks) if I don't select all and change the clip's time base to absolute before I convert a track to a tempo map using this new function, they will move all over the place when the tempo is added.
 

Thanks for incorporating this feature and making the video to show how easy it is. Am very impressed!

Going back to the OP, distorted guitar is pretty much a worst-case scenario for any kind of tempo detection.
 
For the old school method, which is based on amplitude transients, it's bad because there are rarely significant transients in a heavily distorted guitar. It's fairly steady-state, as amplitude goes.
 
The new Melodyne thing, based on watching some of their videos, is clever in that it works off some kind of overall musical pulse. Which means it can extract tempo information from fairly non-percussive material. But again, distorted guitar doesn't contain much of that either.

It only makes sense. If your clip is referenced to M:B:T when the new timeline moves the original absolute time to a new M:B:T location, the timing will be off.
Ex. original
Project is set to 60 bpm
1:1:0 is at 0 seconds
2:1:0 is at 4 seconds
3:1:0 is at 8 seconds
4:1:0 is at 12 seconds
(the click is out of time)
 
the NEW timeline
1:1:0 is at 0 seconds
2:1:0 is at 4 seconds
3:1:0 is at 8.5 seconds
4:1:0 is at 12.7 seconds
(the song is slowing down, click is now in time)
 
Any clips that had properties set to M:B:T before the new timeline should now be out of time. No?
I think if you set the original clips to "absolute time" before the new timeline, you should be okay.
 
 
 
 

Seems like Sonar should say something/offer to fix things when applying a tempo map if any of the audio clips are non-absolute.  Something this page seems to claim happens with AudioSnap tempo changes:
 
https://www.cakewalk.com/...help=AudioSnap.06.html
 

This tempo map thing is frickin' awesome.
 
Again, there has always been a way to hand tool these things, and if you are a Sonar expert it is probably pretty quick and you know how to get the desired results, but this makes it so quick and easy for us lazy folks.
 
It is also a lot of fun to throw songs you love in Sonar and follow the way tempo speeds up and slows down in very popular commercial recordings.   
 
JR
 

Nothing but a big ole bunch of "+1's" from me - really, really good stuff.    And I'm just scratching the surface... although yeah, I find it very interesting to bring known songs into SONAR this way just to see how tempos fluctuate.  It's a great learning experience...

Cracked it!
 
msorrels and jatoth were on the right track. I opened the subject project again ("free" tempo acoustic guitar), bounced all to clips, and then set all the clips to Absolute time base. I dragged the acoustic guitar to the time bar, and waited for the Tempo Map to Generate.
 
Everything is now as tight as can be, with everything that should fall on beat or measure lines falling right there.