Are you wondering what Paul Harvey was referring to when he wrote about a "Top Sergeant"?
We were too, so we did a little research on the MilNet web site. Here's what we found.
http://www.milnet.com/pentagon/enlisted-orig.html
On ocassion when E-9s (the highest enlisted pay grade/rank) abound, the Officer in Command may choose the senior most E-9 and designate him "The Gunny" or "Top", just as a Navy or Space Command Commander may choose a "Master Chief of the Ship". This is an honorary title, however enlisted and NCOs clearly recognized this special title and act accordingly. Sometimes the "Top Sergeant", "Master Chief", or "Master Gunny" at Headquarters will be called "Top", "Chief's Chief", or "Chief Master Gunny" as well. Again there are no such official ranks. Somehow, they do tend to appear in fitness reports, however.
A third E-9 element is the senior enlisted person of each service. The Sergeant Major of the Army (SMA), the Sergeant Major of the Marine Corps (SGTMAJMC), the Master Chief Petty Officer of the Navy (MCPON), and the Chief Master Sergeant of the Air Force (CMSAF) are the spokespersons of the enlisted force at the highest levels of their services. They typically work closely with the Chief of Staff (four star General or Admiral) for their service on all matters pertaining to enlisted personnel. While these remarkable individuals are no longer in the chain of command, it would be rare for anyone, including most junior officers, not to heed the advice or indeed take an order from the top sergeant of the service. The Navy Senior, Master, and Fleet Master, and MCPON Chief Petty Officer anchor metal insignia is for the "overseas" cap. Note that the Fleet Master and MCPON stars are Gold in color.
Sergeant Major of the Army (U.S. Army)
The Sergeant Major of the Army is a unique rank in the United States Army. The holder of this post is the senior enlisted member of the U.S. Army. He is appointed to serve as spokesperson to address the issues of enlisted personnel to the highest positions.