I guess it depends on your relationship to music. Mine is very strong. I'm often aware of the "elevator music" wafting past me in public places, even though it's designed to be completely ignored by the public.
I remember that my pastor from ages 8 to 10 regularly chose "Softly and Tenderly" as an invitational. I don't remember a word he preached, but when someone chose "Softly and Tenderly" as a special a few years ago, it still struck a sensitive place in my heart as it did when I became an altar regular during those years.
I hadn't bought a ticket to a concert for several years until a couple of weeks ago when my husband and I went to see J. J. Heller. Her song that asks "Who will love me for me? Not for what I have done or what I will become?" has really stuck with me since the first time I heard it. How many people around me are asking that question? How can I better appreciate them for who they are today?
There are multiple songs stored away in my memory banks that regularly call me to greater commitment -- "My Soul Desire" by Deniece Williams, multiple songs by Dallas Holm -- "Image of a Man," "If All I Ever Knew," Though He Slay Me" -- "What If I Stumble?" by DC Talk, "The Smell of the Color 9" by Chris Rice (which I have quoted in multiple threads around here) and others by him, "Blessing in the Thorn" and others by Phillips, Craig, & Dean, "There is a Line" by Susan Ashton, "The Anchor Holds" by Ray Boltz. More recently, "Blessing" by Laura Story came up multiple times in a local radio station's play list with such perfect timing that it seemed God's fingerprints were all over it.
There's not a single sermon that has had as much impact on my life as any one of those songs. A few books might be in the competition, but not many and they aren't nearly so accessible to my memory. Recorded music is memorable, repeatable, and, in my case, a powerful emotional experience. It can make me dance, make me cry, and make my heart soar and my faith surge unlike anything else in the world.
The idea that recorded music has "little impact in furthering Christianity" is foreign to me. I'm more in line with a song from the group "Truth". It is so old (80s?) and so fuzzy in my memory that I can't bring up the words in Google, but it tells several stories of troubled people sitting in church and being caught up, not by spoken words, but by the music pulling them to a point of decision and transformation.
Still, I'll agree with you that there's probably a lot of devotion to professional Christian music and the musicians that make it that has little to do with spiritual formation. All the inordinate attention given to music that doesn't appeal to me surely falls into that realm.
Marsha