WASHINGTON — At a packed basement bar on M Street in Northwest, musician Hunter Lang played the often-requested “Piano Man” to a fervent crowd on a mid-September night.

The Billy Joel tune is one of the most requested songs at the Georgetown Piano Bar, and Lang admits it can get a bit tiring to play — but not that night.

“At the last chorus, I stopped singing and dropped out and everyone else was singing, and you could feel the floors vibrating and people were swaying back and forth,” Lang says. “I was like