The VLB music bar which has become active on some members' accounts has a mechanism which can be used to turn it off. Although the buttons which would be visible on VLB are not present, the functionality is still there, and if an affected member clicks on that spot where the "off switch" would be, it can be turned off.
The window still remains on screen though, transparent, and may be turned back on by clicking on the same spot. This is why some members were not immediately affected - they did not have it turned on at first, but accidentally clicked on that spot on their screens which turned it on.
Please see the following screenshot for more precise information on where to click to turn the orange bar off:

In this case, clicking in the area indicated by the red coloring in the screenshot will turn off the orange bar, making it disappear.
We are working on a full solution to this issue, but as it requires a client-side release, a permanent solution is some time away.
We apologize to those affected by this issue.
-There Customer Support