Well, THAT sucked. After much futzing (hours worth) I figured out the problem. In OS X speak "Mic access" means access ANY audio input devices. My laptop had a security burp (possibly brought on by an update, unsure) that revoked mic access to most of the apps that previously had it -- including mixlr. I eventually sorted out that problem, then got mixlr working with both of my audio devices. A casualty in all this was 3 years of show recordings. I have them backed up, but now I have to fish them off Time Machine, which will take several hours. /wrist as the kids say.
Show will probably be on tomorrow night.