Actually I don't think the comparison between Abba and The Beatles is that far off the mark.
If you compare, say, "She Loves you Yeah, Yeah, Yeah" to "Waterloo" or "Help" to something like "Eagle" then the common denominator is just that they both have great pop melodies. And The Beatles were just about the first 'boy band' right? (Ooh! Contoversial!!)

Besides, who can forget the time that Bjorn spent 3 days in bed with Bob Dylan before Dylan went on to record his classic "John, Wesley, Anna and Frida " album!! :)