It used to be inconsistent. I have heard songs that were sung loudly, enough that it would damage your hearing if continued long enough. However, I have seen plenty of songs that the first verse was barely audible. I have heard it get down to the final verse before anyone sings on one song.
And the quality was also inconsistent. There were singers that were just plain terrible in singing. There were other singers that were at least halfway competent, but their talent was totally wasted singing this sxxx. I think dragging the needle across the record would actually have been more entertaining--as was when they got the wrong tape or CD in the player.
Bear in mind that this was before that new songbook came out. I never heard any of the new Kingdumb maladies, and I intend to keep it that way. (Technically I did hear two of them--the two that were left alone, but I forgot which ones.) Now I imagine the singing is much worse.