As soon as I got done asking for Sam songs, I found out that I may be riding Willie, show name The King’s Will.
Given the input “Willie”, iTunes comes back with oodles of Willie Nelson, as one might expect. Also, there are many songs by that title but by artists of whom I have never heard. Not that my lack of knowledge means diddily. Outside of Broadway show tunes & Barry Manilow, I am a musical void.
Suggestions for Willie or regal-related songs?
Virtual Brush Box 
Is there a “Free Willie” theme song?
I’d go with whatever suits horse rather than trying to fit song to horse.
And anyway, if he’s “King” how about “King of the Road”?