"...all music is superficial..."

!??!?!?!??!?!?!?!??!?!?

I would argue the exact contrary -- that music can provide a depth of expression a least as great, if not moreso, than *any* other art form. And song, certainly, includes the literal meaning of lyrics enhanced by the musical setting. For an artist trying to convey a spiritual message, songwriting provides at least as effective a means as anything else he'she might attempt.

Now, whether any spiritual communication actually takes place depends as much upon the listener as upon the artist. And in the (very common) situation where a performer is interpreting another person's songwriting effort, there are three (or more) individuals in the mix, all of whom need to be "on the same page," all taking each other seriously, for a serious message to be conveyed.