Want to record cello track to complement Recorded MP3 audio track. Using usb condenser mike and getting no response in playback. Settings are a problem.
First, please read this post and give us ALL the details requested there about your computer, version of MM which you have and especially about your soundcard/audio interface.
The problem is likely to be, either you have not selected "Audio record" (see the screenshot below) or your audio driver is not correctly set.
Make sure the highlighted box says "Audio Record".