An interesting question. The quick answer would be that all of those things are important. A more accurate answer is that it depends on the song.
For instance, back in 1995, a friend turned me onto "You Oughta Know" by Alanis Morissette. I was putting together a mix tape of breakup songs. She informed me that "You Oughta Know" had to be on it. She quoted some lyrics:
And every time you speak her nameMorissette's raw, angry lyrics expressed my raw, angry emotions perfectly. They pulled me in. The music? By itself, it was nothing much. The melody didn't do anything for me. Morissette hadn't quite mastered the art of singing yet. But that didn't matter. The music fit the words. And yes, she made it onto the mix tape.
Does she know how you told me you'd hold me
Until you died, till you died
But you're still alive
On the other end of the spectrum are tunes like "Love Rollercoaster" by the Ohio Players. I was listening to this gem the other day in the car, singing along, and it suddenly occurred to me that most of the song only consists of two phrases. These are:
Rollercoaster ... of loveand ...
Rollercoaster ... ooh oooooh oooooh ooooooh
Your love is likeWithout having to ask, I know that Don would hate this. His tastes run toward songs that tell stories and contain deep metaphors. He likes Bob Dylan and Paul Simon, and, yes, Cinder Bridge. Songs with inane lyrics over catchy melodies make him run screaming, hands over his ears. I can respect that.
A roller coaster, baby, baby
I wanna ride
On the other hand, could you even imagine "Love Rollercoaster" with profound, Dylanesque lyrics? Here—I'll make up something sensitive and thoughtful, and you sing the words to the "Rollercoaster ... of love" part of the melody:
There's a place inDoesn't quite work, does it?
Where I hide from
The world outside
Which leads to a realization. It takes a special kind of talent to write mindless words that simply feel good to sing along to. That sounds sarcastic, but I don't intend it that way. For all the songs I've written, I'm not sure I'm capable of something like "Love Rollercoaster."
It might be worth trying someday. Challenges like that are a good way to avoid falling into a creative rut. The irony is that it would be ten times harder for me than writing something intelligent.
And for my trouble, Don and others like him would assume I'd gotten lazy.