I came across this tonight while researching the name and performer of a song I remembered from WKRP in Cincinnati. I've never made the connections claimed here or even the claim before. Have you?
According to published reports, “The Boys Are Back in Town,” the only U.S. hit for the Irish rock band Thin Lizzy, borrows part of its melody from “Kitty’s Back.” Most people cite Mike Putterford’s 2002 book, “Phil Lynott: The Rocker,” as the source for the claim. According to the book, Lynott was struggling to complete a song called “G.I. Joe Is Back in Town” about a Vietnam soldier coming home after the war. Lynott eventually changed the song to a story about a group of friends hitting the town but still couldn’t quite get the music right. At the suggestion of producer John Alcock, Springsteen’s “Kitty’s Back” was used as the basis for the bass line, guitar breaks and vocal phrasing in the newly retitled “The Boys Are Back in Town.” Although it may be hard to recognize the similarities when you only hear the songs occasionally, one listen to the two songs back-to-back is all you’ll need to hear the similarities.