Remote patrol

Possibly the only thing tougher than procuring a ticket to a taping of "In Performance at the White House" would be finding someone with a high-definition TV set to watch it on. Tonight's broadcast, at 7 on Channel 19, is the first HDTV production to be taped at 1600 Pennsylvania Ave. Accordingly, KCPT will carry the HDTV simulcast on its digital signal, Channel 18. If you're lucky enough to walk into the right electronics store at that hour, you can watch Patti LuPone, Jennifer Holliday or Brian Stokes Mitchell in brilliant 3-D-like color. (This program was taped Nov. 30, 1998, in the days leading up to the president's impeachment. Amateur psychologists may want to consider that when gauging the official response to the performances.)