Biblical illiteracy (like that's news)

I knew I wasn't going to be able to watch U2's appearance on 60 Minutes until midweek, but I did read some of the reports of it, and was confused by a quotation I saw a few places but cannot now find again (perhaps it's been corrected.) It referred to Bono as having said that as for the Beatles, U2 "cannot touch what he called their 'hymn.'" Other than conjuring up unwanted M.C. Hammer pictures, this sentence didn't communicate much to me; however, I figured there'd be a fuller explanation of what "hymn" referred to (the Beatles' whole oeuvre? their particular style?) when I saw the show. Well, of course, it wasn't a hymn....