I know I'm missing something here, but if I have two audio tracks in my source monitor, how do I only get it to play back with one of them soloed without loading it into the timeline?

Am I missing something easy here?  I think I've done this before, but for the life of me I can't figure it out now...

Thanks.

 CTRL click on the monitor icon to the left of your source audio track display. It will turn green and solo that track.

Or you could also just disable the monitoring on the one you don't want to hear.

 On source side of the time line, you could individually click on the track monitor button (left most buttons on the timeline display) to turn off the track(s) you don't want to hear.  If you want to solo a track, hold down the CTRL key while clicking the monitor button on the track you want to solo.