I discovered his "all right but I don't want to do it" vocalization.

In the past, went I went into a room and closed the door behind me, he would stand at the door and scream until I came out.

So...I tried making that noise (all right but I don't want to do it, that he makes) back to him, and lo and behold, it WORKED/WORKS! He shut up immediately and sat down quietly and waited.

It was hilarious!

It must be a noise a mama cat makes to the babies when she wants them to do something that they don't want to do. That's all I can think of...I know, far-fetched, but he is an ALC so I try everything to communicate with him in a successful manner.