To me, the blues is an infection. I don't think it's necessarily a melancholy thing; the blues can be really positive and I think I think anyone and everyone can have a place for the blues. It need not always a woeful, sorrowful thing. It's more reflective; it reminds you to feel.
In contrast, Christianity, while acknowledging the presence of suffering, declares that life can be infinitely worth living and opens the way to eternal life in fellowship with God Who so loved the world that He gave Himself in Christ.