Ron—-Got It!!!
It was Multicast on the Linksys Router.
Several websites have the directions for Multicast on a Linksys router wrong.
It’s called “Multicast Filtering” under the Securities Tab.
The directions are not intuitive and say that you leave the setting to “Disabled” so you don’t enable any filtering on Multicast. (Makes sense)
This is wrong—-when you set the setting to Enabled—-you Enable Multicast.
Found this out when I googled Multicast on Linksys Routers—-sure enough—-several people have run into the same thing—-and there is even an Apple support thread on the subject…..
I now have a Shared Music Tab on the left hand side in both my iTunes—-and music plays just fine off the HP Server.
Thank you so much for sticking with me on this.
GREAT help!!
Happy New Year to you and yours.
John