That'd be InStore Audio.

www.instoreaudionetwork.com/in2/contact.html is their contact page, I believe if you send them a polite e-mail with your store number, date, and exact time, they can tell you what song played then.

Since Kroger and Walgreens both use that same network, this thread from Topix might also be helpful: www.topix.com/forum/com/wag/T4Q8RSO19D8M8PNMT/