The Beatles on “Ed Sullivan.†Michael Jackson’s Moonwalk on the “Motown 25th Anniversary Special.†Ricky Martin at the Grammys. Each of these TV appearances launched a musical career into the stratosphere. On Wednesday Feb. 12, 2003, Jill Sobule appeared on “The West Wing.†Will lightning strike again? If you watched the episode, you may have seen Sobule, the singer-songwriter best known for her hit “I Kissed a Girl,†playing two songs in a bar as Toby and C.J. argued a…