But I got one question:
What does "yodelay-hee-ho!" mean?

Don't mean squat ~ just conveys feeling, like doo-wop or scat or Celtic mouth music, or any kind of non-verbal vocalizing where the voice functions as an instrument.

I should own up to the fact that I only developed an ability to yodel because I was such a dismal failure in my efforts to progress from streetsinging to actual paying indoor gigs. Two or three years of busking for long hours made me develop a thick skin and a give-a-shit attitude, and also kept me in a position where the single most important thng to do was to be LOUD. Ideal conditions for an apprentice yodeler!