I would like to add one more perspective from different angle: The quality of recording.
If the quality of recording is not that good, how can the demo or any recording impress the targetted audience?
So here are some important questions:
1) Who are the audience? Are you trying to sell it or are you trying to give it away and to whom? That is one aspect that DNJ talked about.
2) What kind of equipment you have and what budget have you allocated for this? This question is important for quality recording but at the same time is tied to the first question. Are you planning to do something for friends? Maybe quality is not that important as long as it is decent (no distortion).
Let me suggest one important factor to consider that many do not think it is important: A mixer or any device that has pre-amp. And keyboard connected directly to a sound card is not the best way to do it; though it is better than connecting a mic directly to sound card.
We can all work with you all to do what you want.
[This message has been edited by sk880user (edited 10-06-2003).]