To find out what version of Android your running go to settings and scroll down to about phone and tap it now about half way down you'll see the version your running.
There no way to uninstall updates and there's a warning before you update that will tell you this before you agree to update.
Why won't the music player work on the phone due to an update to the phones OS?
Thanks. I found out that the new version is 4.4.3.
Fortunately I did not allow the update, and have since cleared the cache of the updater app which seems to have eliminated the installer nag, and hopefully the update file as well. With automatic updates turned off , I will be ok moving forward.
The music app I use needs to have access to the SD card, which, according to the developer, is an issue that they cannot work around with 4.4 - it has apparently has limited SD card access.