Weird Back/Shoulder Pain Question

I have a strange pain in my back and/or shoulder that I have been getting for years now. It usually happens when I'm standing for a long period of time (think music concert) or running. It happens above my right scapula between my scapula and the center of my back, just below where my neck is. It usually isn't much of a problem, but I'd love to know if there is any isometric exercises I could use to strengthen this muscle and try to fix whatever is going on there.