Like GSE, I think in the best songs, all the elements come together (syncopation?) to make a memorable song that moves people in some way (to laugh, to cry, to think, or just to dance).
I also think that if one element is particularly strong, it can make up for weaker elements. I may be alone in my opinion here, but Bob Dylan's songs were strong in the lyrics department, and his playing was better than average. These two combined to make his vocals a non-issue. Bob was never known as a voice, but as a poet.
Likewise, the strong rythm and backbeat along with unique and pleasant vocals of many performers from the 50s carried somewhat weak or cliche lyrics. (The Everly Brothers, Buddy Holly, and Ricky Nelson come to mind).
Another approach is to be so unique, as to demand attention. Johnny Cash had absolutely no vocal range, and mediocre guitar playing skills, but his unique sound and "bad boy" persona made him the sensation he was, and still is!
Interesting thread, it will be neat to see others' responses.
Just play