Staffers may have heard piano music coming from the Capitol last week as Sen. Lamar Alexander tickled the ivories in his Senate hideaway.

We hear the Tennessee Republican was practicing day and night for his Saturday performance at the annual Alfalfa Club dinner.

At the dinner, Alexander, a classically trained pianist, played several humorous songs that he wrote for the occasion.

A tipster tells us that he opened with a retooled version of “My Favorite Things,” with one stanza saying, “W’s new book has become a best-seller, he’s unemployed now but still a good feller.”

Alexander’s sense of humor didn’t stop there. Between songs, he cracked jokes, including one at Chicago mayoral candidate Rahm Emanuel’s expense.

“President Obama and I are complete opposites,” he told the crowd. “I’ve actually hired people who don’t live in Chicago. Although, technically Rahm doesn’t live in Chicago.”

Alexander showed a more serious side at the conclusion of his performance when he told the crowd to “find the good and praise it,” before playing “Amazing Grace.”