Copied from another thread to this section:
 
"I've been importing some .WAV files of old songs to start rebuilding them from scratch.  Is there any way I can have SONAR X3 analyze or process the resulting audio tracks to determine the tempo of the imported songs?"
 
I've had more than 50 views, but nary a single reply.  I understand that this feature might not work on all songs, and the information the program works on might have to be limited to percussive instruments initially.  
 
Any comments in the meantime?  Thanks in advance.

I start with a click or a kick track, select transients from the edit drop down menu, open the Audiosnap palette, adjust the threshold and select set project from clip. I usually get it pretty close with that and then tweek it. This video form Karl ( Fast Biker Boy ) should help: https://www.youtube.com/watch?v=7VR7WkHywTo
 
Rocky

[This part is more of an aside, since not sure the "end purpose of the bpm...]
I put a similar feature request out about a month ago for the same reason as the OP. For me, AudioSnap requires excessive overhead and has been rather flaky with results even when feeding it properly. Within AS, it would be nice to tweak the algorithm with an audio microscope, but this still requires "man handling."
 
The real reason I had posted that request was I had picked up Riffstation (still on sale, with a trial version available) and was randomly opening commercial masters (not individual tracks) and the bpm was correct in far more cases than AS gets, and I needed to do nothing more than open it. I was incredibly dismayed to see this since many of the ones I eventually opened did not have highly defined percussion/bass.
 
I just got that VST to play with it, but its ability to extract accurate bpms stuck out the most (each file must be opened discretely, of course).
[end of the aside... more FYI unless "just average bpm" is desired]
 
[Most practical method within SONAR...]
From another standpoint... if importing an old wav file, using Shift-M to define beats in the song is the best method I have found to set a tempo map for the project. Is fairly clean and quick. Once that tempo map is set, the song can be embellished with MIDI/VSTis easily.
 
Using this method, you can open a song, lock the first beat of your choice, then go out several bars and lock that one... the region between the two will have the bpm you have set (manually), but if importing a wav and intending to embellish it, using Shift-M throughout the song is the best way to accurately map the tempo (since it can easily have variations to throw off MIDI).

I've always thought that it would be cool to have handles attached to the measures/beats grid lines.  These handles would allow you to grab them and pull them so that you could align them to your waveform display.  After you let go of the handle a tempo map would be created between any previously moved grid lines and the one you just modified.
 
However, that could get complicated as you drag grid lines across the screen and cross other grid lines.  But, I just get ideas and let someone else figure out how to do it, if it sounds like a good one.

Dave Modisette
I've always thought that it would be cool to have handles attached to the measures/beats grid lines.

That's basically what Edit Clip Map does in Audiosnap, but it's per clip and you don't usually set the project until you've finished mapping the clip (or at least remapped any beat markers that SONAR got wrong).
 
That said, like Michael, I generally prefer using Set Measure/Beat At Now.