Is there a code or script I can use to make streaming audio? The MP3 cannot be visible for "clever" people to download.

To make true streaming media you need a streaming server. Any progressive download media can be saved, especially by clever people. Heck, clever people can even figure out how to save streaming media.
If my media was so good that people wanted to save it and share it, I'd be flattered, not worried about it.

Are there any free streaming servers?
It's streaming a band's song that the label doesn't want downloaded, which is why it's not supposed to be saved. I didn't realize streaming could be saved (other than actually ripping it).

Streaming music is data, and as such can be "captured" along with any other data that's introduced to a computer.

Then why don't you just put up a "preview", or rather "presound", rather then the whole song. People could only hear a couple of seconds of the song, like in Apple's iTunes Musicstore. With maybe a buy button next to it. No streaming needed then.

Perhaps they should investigate getting their music placed on the iTunes Store.
http://www.apple.com/itunes/musicmarketing/
http://www.apple.com/itunes/musicmarketing/faq.html