The AirPort Utility (regardless of version) is NOT required for streaming iTunes to the AirPort Express. It IS required if you want to administer the base station. There are actually two versions of the AirPort Utility that runs on OS X Lion: 1) v6.0 which has an iOS-like interface and is somewhat limited in functionality, and 2) v5.6 which has the traditional interface and is more full-featured. Both can be downloaded from Apple's Support Download site.
Thank you for your response. For my education, Airport Utility is what connects me to Airport Express? What do you mean it is not required to stream itunes to the Express? My bose speakers are attached to the express and I couldn't get the music to play thru them. Will updating my version of Airport Utility give me the option, when in Itunes, to chose the speakers attached to the Airport Express? Please advise.
For my education, Airport Utility is what connects me to Airport Express?
No, your wireless adapter is what "connects" you to the AirPort Express. The AirPort Utility is primarily used to administer the Express to configure it for your networking needs. Other manufacturer's wireless routers typically use a web-based administration interface, whereas the AirPorts use the AirPort Utility for this function.
What do you mean it is not required to stream itunes to the Express?
Once AirPlay is enabled ... something that you DO configure using the AirPort Utility, the utility itself has nothing to do with the actual streaming. You could (theoretically) remove the utility and steaming will still occur.
Remember this AirPort Utility is the means to configure/administer the Express, but it is NOT required to connect to it or for streaming.