What are your precise system specs? XP? Win7? Win8? 32-bit? 64-bit?
Sonar X1, X1c, X1d? Producer Edition? Studio? Essentials?
Most of us - you will see at the bottom of this post, include our system specs in our forum profile's signature. That helps people figure out what we are using for hardware/software and makes it much easier to help the person with the problem.
So, please, edit your forum profile, clicj the signature tab, add your specs, then make sure to check the box at the bottom that tells it to add your signature to all of your posts.
Can you please provide more detail as to how you have your midi and audio tracks configured? I am looking for whether or not you are using 'simple instrument tracks' or a regular audio and midi track.
As a simple example, you need the following present and connected the correct way to be able to trigger midi sounds in Sonar that end up going through an audio track to your master buss and then through your audio interface to your speakers:
1. You must have your audio interface drivers properly installed and working - seems like since you can hear your guitar backing tracks this is working
2. You must have some sort of synth loaded into the synth rack, with a preset loaded.
3. You could have a simple instrument track, but skip that for now. You need a MIDI track that has its output set to go to the synth in the synth rack
4, You need an audio track that has for its input the OUTPUT from the soft synth, and the audio output should be sent to some buss - the Master bus is the default so you do not need to change that for now. Later on, you will learn about using multiple buses and such - skip that for the moment.
5. The Master bus must have its output going to your audio interface.
There are some basic tutorials in the Sonar documentation that it sounds like you did not read, and/or did not do. These will get you up and running with a midi/audio example that work.
I hope any of the above helps, because I am hungry and done typing,
Bob Bone