Several good ideas have already been provided here.

It's a little known fact that microphones are notorius for altering the pitch when we sing or play an instrument such as the fiddle. I still shudder when I listen to an old tape recording I have on which I seem to be playing out of tune. I'm sure that better microphones would have solved the problem. <g> I'm pretty sure microphones have even thrown my guitar out of tune on occasion though I can't prove it. <vbg>

Another idea that might be helpful is to use your computer to help you practice. Your computer may have a built-in microphone; if not, it will have a microphone input socket. You can use your computer's built-in software to record yourself playing and singing and critique your performance. If you can get around the feedback, you can also leave your computer's speakers enabled and use the whole setup like a monitor at a performance.

      - Mark