Have imported a wav file into project at 120.  Change project tempo to 90.  The waveform changes and gets shorter, but on playback, it still plays at same speed, even though clip is shorter?  Can someone explain how to do this?  ty
 
(In Samp you change the project tempo and have option to change every object in proj.)

cntr+L to create a groove clip
 
 
the wave file might look shorter after changing tempo, but its the grid that changing. you can also ctr+drag the end of the clip to stretch it to the nearest bar. 

Process > Fit to Time. When the dialog box appears, click on the Help button for more info.
 
Note that this can take a while. Sonar uses the offline iZotope stretching algorithm for maximum fidelity; there's no real-time preview.

If I have an entire project, rythym guitars, bass, programmed drums, is there an easy way to change the tempo of the entire song/project.
 
A typical scenario for me would be to slow down a song while I'm working out solo parts, then speed it up.   Fit to time seems to work at the clip level.  In Samp I just change the project tempo and I'm given an option to conform audio and/or midi to the new tempo.

I seem to recall this question coming up before, and someone had an answer (maybe scook?). I've never checked into this myself because I don't slow things down to learn a part; I have to play anything I do in real time because I could end up needing to play it live. 
 
I don't believe Sonar has a "push a button and everything conforms" option unless you're using Groove clips, in which case you don't have to do anything other than change tempo. If you're just doing this to preview at a slower tempo, then converting everything to groove clips would have no sonic penalty except while previewing (and the penalty would depend on how far you had to stretch). As soon as you went back to the original tempo, any groove clip editing becomes transparent. You can simply turn off groove clip looping if you want when you return to the original tempo.
 
Another option would be to create a premix, slow it down, and play to that. For example, suppose the premix is 24 measures long and you use the ctrl+slip edit to slow it down so now it's 30 measures long. You play a part along with it and the new part is 30 measures. Slip-edit the new part to 24 measures and now it will be at your original tempo.

Anderton
I seem to recall this question coming up before, and someone had an answer (maybe scook?). I've never checked into this myself because I don't slow things down to learn a part; I have to play anything I do in real time because I could end up needing to play it live.  

OK, I realize you are a moderator and well esteemed around these parts, but this is cranky old man stuff.  If you can shred 1/32nd note arpeggios up and down the neck without working them up to speed first, then you are a guitar God.  When phrases have loose timing or switch between quarters and triplets within a phrase, sometimes you need to slow the music down to get the timing right, a metronome always doesnt do.
 
That doesn't even address the writing aspect.  If you can write 1/32nd note arpeggios and melodic phrases in real time you far surpass the great classical masters.

Teal

Anderton
I seem to recall this question coming up before, and someone had an answer (maybe scook?). I've never checked into this myself because I don't slow things down to learn a part; I have to play anything I do in real time because I could end up needing to play it live.  

OK, I realize you are a moderator and well esteemed around these parts, but this is cranky old man stuff.

Here you go - you don't even need to leave your mom's basement to read it-
http://www.audible.com/pd...-ksPKGIYy4CRaKjCvD_BwE

Teal

Anderton
I seem to recall this question coming up before, and someone had an answer (maybe scook?). I've never checked into this myself because I don't slow things down to learn a part; I have to play anything I do in real time because I could end up needing to play it live.  

OK, I realize you are a moderator and well esteemed around these parts, but this is cranky old man stuff.

No, it's just the reality of the situation. For me recording is prep work for playing live. I thought I at least needed to explain why I've never looked into this because people do ask about it, and it seemed kind of lame to say "yeah, I remember something about this, someone had an answer" and leave it at that. Perhaps if I'd put the "have" in "have to play anything I do in real time" in Italics you would have taken it correctly as a statement of how my world has to work, not a value judgment on how you do music, which frankly I couldn't care less about unless you have some really cool tip about how you do things that I can use...it's up to you to make music in whatever way you want. And I have the right to play everything in real time if I so choose and if that limits me, I really don't think anyone cares.
 
Note that I gave you two possible ways to do what you want, with absolutely no value judgments attached and in a spirit of trying to help; in return, I get a rant about 1/32nd notes. Well, I have MIDI, keyboards, and step time for those  Right tool for the right job, and all that. I'm aware of my limitations and work within them, which is what that first paragraph is about. I'm sorry if it wasn't clear enough for you to interpret correctly.