The language isn't just the words we speak every day. There are any number of words I use in writing that I probably don't in speech, and even more which I recognise when reading which I probably wouldn't use in writing.

Generally speaking it's better to stick to spoken language in a song. But all rules need to be broken sometimes.

I'm surprised that, with all these Dylan quotes and discussions of "wax", noone has yet quoted "Gates of Eden":

Upon four-egged forest clouds
The cowboy angel rides
With his candle lit into the sun
Though its glow is waxed in black
All except when 'neath the trees of Eden,/I>,/B>

(Well that's what the book says - but I think he actually sings "waxing black")