You can use Sonar's transpose function to lower (or raise) the pitch of a midi track.  It is located in the Process menu and you adjust the pitch by the number of half steps.

Kamie
ok I use van basco midi player in wich you can mute undesired channel but the important thing for me is the key note
in van basco I can adjust this key to fit my voice and save it with the chosen key into a playlist Before I had sonar Le and I could select an option in window xp sound setting that allowed me to record speakers sound with wich is not available in window 7 . I loaded the midi in sonar le and open a wave track wich was recordind the speakers sound.
Is there any way to do this? Can I change the key in Sonar artist?

Hi Kamie. I think I understand what you want to do.
You want to record what you hear in the speakers on your PC.
Have a look at the following on how to enable 'stereo mix', as an available recording source in Windows.
 
 
 
If that doesn't work for you, then you could also use an audio cable to route the line output from your soundcard to the record jack on your soundcard. This approach is mentioned in the above article as well.
 
You can also download a free Windows program called VoiceMeeter from VB Audio which will take
what you hear on your speakers as an input and output that audio as an available
recording input to programs such as Sonar. However, if you are not very technically minded you might
find VoiceMeeter a bit confusing. I use VoiceMeeter to record what I am hearing on my speakers,
since my laptop's soundcard driver doesn't seem to offer up the 'stereo mix' option mentioned above.
 
 
P.S. It looks like the forum is blocking the web links I posted above, so search on the following in Google:
(from How-to geek)
"How to Record the Sound Coming From Your PC (Even Without Stereo Mix)"
"How to Enable “Stereo Mix” in Windows and Record Audio from Your PC"

and search for "Voice Meeter VB Audio" to find the VoiceMeeter website.
 
 
All the best.
 
 

If you had Sonar Professional, the easiest way to do this would be to keep it all in Sonar.  You can now record the MIDI instrument track audio directly to an audio track within Sonar, in the box.
http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=Mixing.14.html
 
To do this, setup a MIDI track, and select the MIDI clip in the clips pane and transpose it to the desired pitch using Process > Transpose.
 
Then route the MIDI instrument output to "New Patch Point".
 
Insert a new audio track, and use Patch Point 1 (the new patch point) as the input for that track.  Arm it to record.  The MIDI instrument will record it's audio output there.
 
Setup another audio track and set it up for your microphone input.  Arm it to record.
 
You will end up with two audio tracks, one for your MIDI instrument's audio recording, and the other for your microphone audio.  Then you can mix and do whatever.
 
And I do remember, back in earlier versions of Windows, using a Sound Blaster that had a "what you hear" option as a recording source.  Don't know what's become of it with Windows lately, but I did discover you can still do this in Linux.