Depends on the song. I play a lot of tunes from the 20s-40s and many of them were cranked out by songwriting teams looking for a popular hit, not passionate artists. Even some of the greats, like Fats Waller, wrote songs where the lyrics were catchy but when studied alone, were awful as poetry.
I play pop and folk songs from the early 60s-mid 70s, too. And while there are some truly incredible songs - by people like Bob Dylan, the Beatles, James Taylor, Randy Newman, Fred Neil and others - they all produced fluff, too. Pop, catchy fluff at times, but fluff nonetheless.
A good song is a gestalt. It works as a whole, not in pieces that can be removed or dissected. American Pie and Where Do You Go To My Lovely are good examples - start to analyze the lyrics and you'll find them confusing and opaque. But as songs - they're wonderful. A lot of Bob Dylan's music is like that, too.
