Hi, sorry if this is such a basic question – before posting here I've looked through the manual, the online help, the Groove3 tutorials, and Scott Garrigus' book. I'm using Sonar X3 Studio.
 
What I want to do is summarized in the title of this post. I have an audio track which in this case is 100 bpm. I want to accompany it on a keyboard, but I'm not so good, so I need to slow it down so I can keep up. (I don't want to step record in this case, as it would take a long time and not be nearly as fun / effective as when I play in real time.)
 
If this were a midi-only project, i.e if both the track I'm accompanying and the accompaniment are midi,  I'd know what to do – just change the tempo to, say, 75 bpm, record myself at the new tempo, then restore the original tempo of 100 bpm, and we're done.
 
Similarly, in my old DAW, Acid, I can easily do what I want when audio is involved. That is, I can set up a new project with a tempo of 100 bpm; import my audio file as a “beatmapped” clip (similar to a Groove Clip); set the project tempo to 75 bpm; record the midi; restore the project tempo to 100 bpm; and again, I'm good to go, as both audio and midi are re-tempoed correctly and in-sync. I don't have to do any math (see below).
 
But with Sonar X3, when audio is involved, I get messed up – despite trying things like
 
– converting the audio to a Groove Clip (admittedly haven't worked with these yet);
– using Process >Length; and
– using the offline Time/Pitch Stretch 2 effect.
 
While with varying degrees of success I can slow the audio down (by the way, I know that audio quality suffers during stretching; I am not expecting it to sound pristine, I just need it slow enough to temporarily monitor so I can accompany it on keyboard) I get messed up, because while the audio is now at the slower tempo, the project tempo remains the same.
 
It is not clear to me how to adjust the tempo for recording – if I tell Sonar to make the audio, say, 25% longer, does that mean I should make the new project tempo equal to (100 x .75) = 75 bpm, or equal to (100 /1.25) = 80 bpm?
 
And once I'm done, I'm having trouble restoring everything to the original tempo.
 
I apologize if I am overlooking something basic. I would be very grateful if someone could give me a steer, in the form of idiot-proof steps to do this, assuming it can be done.
 
In a pinch I guss I can just do my midi recording in Acid, and export the resultant midi into Sonar. But this has some drawbacks, e.g. I can't loop record midi or comp in Acid; and it clogs up workflow, as I'm trying to do as much as I can in Sonar, having invested a fair bit of time learning this basically amazing DAW.
 
Also, a tangential question … in this case I know what the tempo is. But what if I don't? Recently I recall importing an audio track, and in the track inspector, under Clips / Groove, seeing that Sonar had estimated an average tempo. But today, I tried again, and must have done something different, because it only displayed the default project tempo of 120 bpm. What do I do to get Sonar t estimate the tempo?
 
Really grateful for any help!

Anyone?

I'm in the middle of a bunch of crap right now so didn't read through the entire OP so maybe you have already tried this...
 
What I have done in the past is turn any audio clips into GrooveClips. GrooveClips will follow tempo changes. They may sound like crap though and this is a MASSIVE PITA if you have a ton of audio already recorded.
 
Therefore try this. Do an export of your project as is (at least of all the audio tracks). Insert a new track and import the export you just made into that track. Turn that clip into a GrooveClip (so it follows tempo changes). Mute all other tracks (except MIDI tracks if you did not include them in the export because MIDI tracks will of course follow any tempo changes without any extra futzing about).
 
Now all you should be hearing is the track with you now GrooveClip export track that will respond to tempo changes (and any unmuted MIDI tracks if you left hose alone).
 
You can slow down the tempo and record to JUST that track. The muted audio tracks will not follow the tempo changes of course but you cannot hear them anyway so it won't matter and they will sync back up once you go back to the original tempo.
 
The ONLY drawback to this methind is that the quality of the GrooveClipped audio track may not be so great when you change tempos but it should be good enough to record your MIDI parts to. If it is TOO screwed up you could bounced the clip using offline render and it should help clean it up a bit but if you do this copy the clip first and bounce the copy (that way your original export remains intact in case you want to use it for further tempo changes/slow down recordings... just keep it intact... it's wrth it).
 
After you are done recording your new MIDI track all you have to do is speed the project back up to the original tempo, mute the export/groove clip track and unmute all the original tracks. Your new MIDI track will follow the new tempo.
 
Hope that helps.
 
Cheers.

BTW... you HAVE to make sure when you export that backer track (that will be turned into a GrooveClip) is exported from the VERY beginning of the project (00:00:00) otherwise it will not stay in sync during the tempo change.
 
To do that just make sure you have the NowTime set at 00:00:00 (the start of the project) then do your export.
 
I am assuming you are familiar with export functions but I (or others) can offer further advice if you are having a hard time or want to get fancy with the export (like only exporting certin tracks or busses or whatever).
 
Cheers.
 

After reading some of your OP I have overlooked some of the issues.
 
Edit: If you do what I have recommended you just need to change to Project Tempo in the Control Bar/Transport Panel. I should ahve included that in the following. Sorry I'm a little scatterbrained today.
 
Do not use the Time Stretch tool. It is unnecessary for this (but is very cool for other stuff). Just right click the clip (preferably a single clip of the full mix that has been exported and imported from/to the 00:00:00 point on the timeline) and select GrooveClip Looping (or whatever it's called). Alternatively you can just select the clip by clicking on it (it will turn gray) and press L on your keyboard (which is the default keybinding to convert a clip into a GrooveClip).
 
You can also find more information and control for the GrooveClip (or clips in general) by openeing the Inspector (press I on your keyboard) and selecting the Clip tab at the top of the Inspector. This will show you information on the selected clip. Go to the GrooveClips option in that tab and you can see all sorts of stuff and adjust certain options for that specific clip.
 
Good stuff to know/read up on. It's all very cool and useful if not a little wacky. You can also read up on Loop Constructor View which is the beat slicer thingie for looped clips.
 
You really shouldn't need any of that to do what you want BUT as long as you are exploring these areas I figured I'd mention it as they add some power through knowledge to the type of task you are trying to accomplish.
 
Cheers and have fun.

 
Although it may not seem initially "easy" to have to export and import to do stuff like this I actually find it very useful to keep a dedicated track specifically for full mix stereo waves as the project progresses. That would be where I do something like this.
 
Essentially it's full separation from the main mix so I can fiddle with this type of thing without screwing up my main tracks, I can import my various mixes as the project progresses and most importantly keep a version of the original file whether it was sent to me by a collaborator or if it's a cover the original version. That way I can keep using the full mix stereo waves I have imported into that track as reference to see how things are going (I just need to solo a specific take lane and the track to hear that version or leave it active to hear it with the active project) or do stuff like you are proposing easily (choosing a clip and enabling looping for tempo wackiness). It can also house mix references of other finished material so I can check my mixes.
 
Total fan of keeping a full mix/multi purpose track like that. I can also keep notes in the Take Lanes notes section on each stereo mix so I can solo what I need for reference purposes.
 
and now I'm just blathering...
 
;-p

Beepster, 
 
**Many** thanks for your time and help. While you were writing, I was offline, and in fact on the phone with Cakewalk tech support. Together we reached another solution. 
 
This explanation applies to X3e. The solution we reached lies with Audiosnap rather than Groove Clips. Here's what we did.
 
To avoid complications and to lower resource use, I first rendered, as a wave file, what I want to accompany, aka the "Base track".
 
Then...
 
Close that project, start a new project.
 
Drag this Base audio track into the new project. The default tempo displayed near the transport window will show 120 bpm. Ignore this.
 
Select this Base track.
 
In the track header, under the track name, change the filter from the default Clips setting to Audio Transients. Vertical lines indicating the transients will appear superimposed on the Base track in the timeline.
 
Bring up the Audiosnap dialogue (press "a" in X3e). Turn Audiosnap on by clicking the first button from the left at the top of this dialogue. The button will turn white, showing that it's on.
 
Then, over in the Inspector's Clip pane, under the Audiosnap heading, be sure that Enable is checked. Just below that, the Average Tempo will then be displayed. In this example, it is 191 bpm. (This is quite wrong -- in fact it seems twice as fast as the actual track, which is a rather chilled acoustic tune; but as will be seen, this absolute value of 191 bpm is irrelevant; its use here is as a baseline value for the relative adjustments to follow. )
 
Back in the Audiosnap dialogue, under Tempo, activate Clip Follows Project.
 
In the Transport window, change the tempo from the default of 120 bpm to something slower than 191 bpm. (You could leave it at 120 bpm, but it would in this case be incredibly slow, and sound like pure
garbage – basically impossible to accompany.) In this example, I found through trial and error that changing it to 160 bpm makes it slow enough to accompany, without sounding too mangled.
 
Insert and arm a midi track for recording. Record the midi take(s) at this tempo.
 
When done recording, in the Audiosnap dialogue, turn off Clip Follows Project, then turn off Audiosnap.
 
If at this point you pressed Play, you'd hear the Base audio track play normally at its original tempo, while the midi would be out of sync.
 
So the last step is to Change the project tempo to the 191 bpm we saw earlier.
 
Now the audio will still sound normal, while the midi and audio will be in sync.
 
Done. 
 
I forgot to get the name of the tech support guy who helped me, but he was great! Many thanks
 
 

Is this track recorded to click? As in is there a fluctuating tempo or not?
 
All that seems really unnecessary if the original tempo was consistent. What seems to have been described is what you'd do to completely preserve audio quality and/or adjust timing on a track that was not recorded to a click/tempo. Essentially the type of stuff you'd do if you actually wanted to retain the tempo changes instead of just recording a MIDI track overtop of something at a slower tempo then speeding it back up again.
 
There may have been more factors involved though that the support guy was basing his advice on.
 
Audiosnap is notoriously unweildy and best avoided unless necessary (IME). The way I described actually is quicker, easier and more reliable than all that if all you need to do is drop down some MIDI tracks at a slower tempo.
 
However the unknown support fellow did do you a massive favor by pushing you into exploring the much more in depth/advanced areas of the program. It sounds like you got a full on lesson on using a feature that confuzzles and infuriates the best of us so good on ya (and the support fellow).
 
This does show yet again there is more than one way to skin the proverbial cat in this program. I still think the Export > Import > Loop > Slow Down > Record > Speed Up method is logically simpler and easier to execute BUT getting an audiosnap lesson from a Cake support guy is really cool and it worked for ya (which is even better).
 
Excellent.
 
Cheers.

kofgadol
 
Close that project, start a new project.
 

Unfortunately this is what first came to mind for me as well. The "quick and dirty" since you have created a new project anyway is as you mentioned to bounce down or export what you want to play to. Since you do not need "precise" timing, you can simply slip-stretch the audio (ctrl-drag on the right end of the clip to taste). Bounce that to clip(s) if desired, then record the MIDI track. When finished drag that MIDI track into the browser to save it, shift back to the original project, and drag the MIDI from the browser to the appropriate track.
 
AudioSnap, while useful at times, it not necessary for what you are doing.

Thanks for the follow-up comments. 
 
As it turns out, Beepster, the track wasn't recorded to a click, so perhaps that's why Mr Tech support suggested what he did. At all events, a) it worked; and b) though it sounds complicated the way I wrote it (in a "For Dummies" style, for my own later reference if nothing else), it's actually simple enough now that I know how to do it; just a few clicks here and there. 
 
I will go back and investigate the Groove clip approach. I tried messing with that this morning. I don't remember everything I did; I just remember a few different avenues dead-ending on me. 
 
Mettelus -- interesting tips you offer. They show much I've yet to learn (I only returned to the CW fold recently, having left around the time of Sonar 2). Slip-stretching sounds quite cool. I also didn't know that dragging something into the browser saved it. One question though -- how would I ensure that the midi file would sync up with the original project? I assume that in the new, ad-hoc project I created for this purpose, I would have to ensure that its project tempo matched that of the original one?
 
In all, I think it's time for me to revisit the Groove3 videos. I watched them over Xmas break, and between the season's mind-altering consumables and the abundance of detail to take in, I guess a lot of it just washed over me... 
 
At all events, thanks again to both of you.