Can live audio be fed into itunes?

I've been looking for a way to use the visualizer in itunes in a live music performance. It seems to me that it would simply require routing line-in audio into itunes.

I've tried streaming audio via podcast, hoping to find a way to send the audio straight to itunes as a stream. Needless to say, I've been largely unsuccessful. The main issue is always latency.

I know there are relatively inexpensive programs available that can accomplish the task of visualizing live music, but I prefer the new itunes visualizer to any I've seen.

Any advice or leads would be greatly appreciated.
Thanks