>> D.C. looks to be trapped in the middle of a presidential endorsement face-off, with Virginia Gov. Tim Kaine already firmly in the Sen. Barack Obama camp (the first governor to endorse the candidate), and Maryland Gov. Martin O’Malley declaring his support for Sen. Hillary Clinton. Will D.C. Mayor Adrian Fenty step into the fray with an endorsement of his own? >> Police have arrested a 12-year-old boy in connection to the “pins in the…

This is another one of those weeks, when devoted classical listeners could be in one hall or another every night of the week. Enjoy it while you can, as the summer is almost here and with it far fewer concerts to hear. ESSENTIAL: >> A concert by French pianist Pierre-Laurent Aimard is an event to be cherished, and this week he will play twice in Washington. The first occasion is a solo recital at the…

This coming weekend is the last viable one for concerts in November. So we have a pile-up of events on the agenda this week, as everyone in town tries to get something heard before Thanksgiving. After Thanksgiving, it will be time for that dreaded December tradition, the holiday concerts and umpteen performances of a certain Handel oratorio that must not be named. FREE, FREE, FREE: >> This week musicians from two important summer music festivals…