The nature of evangelism is sharing the Gospel - so in that regard, your remarks don't make sense to me.
Then again, as you pointed out earlier, I'm no "Einstein". (Very Christ-like of you, I must say.)
But, it is wrong to use that as a substitute for preaching the Gospel.
It is not wrong to use music in an evangelistic effort - and an evangelistic effort by its nature is the sharing of one's Christianity and the Gospel - through many means. Evangelism legitimately encompasses more than speaking, and just because you're tone deaf (by your admission) does not give you license to challenge the validity of communication through music.
With that, I believe I'm done with you. No matter what I do, I will never be as uptight, stuffy, and traditional as you require me to be. Thankfully, I don't answer to you. I will put my confidence in God's grace to forgive me if I've failed in the arena of sharing my faith through my profession, or in understanding His desire for the role of Christians in music.
"does not give you license to challenge the validity of communication through music."
Ah, but trying to uphold godly standards and being faithful to God does.