I remember playing various bootlegs of Crazy Kong in the arcades of Birmingham, England in the 1980's. One thing I recall quite clearly was the audio. It had a very distinctive tune. When playing the MAME versions of CK, I searched for this particular tune and could never find it.
Thinking I had imagined it, I trawled YT recently and now found a version that matches the sound that I remember. Perhaps consideration could be given to implementing this as I don't think it was unique to just a couple of boards. I heard it all over the place!