Charlie Checkpoint and a Charlie Card

Alice has been singing the old Kingston Trio song, "M.T.A." to cheer herself up about that thin brown wall.
Poor old Charlie, who couldn't get off that Boston MTA subway train, stuck below without a nickel during a fare increase. A couple of years ago, Boston created the "Charlie Card" to allow riders to avoid having to deal with coins and tokens. Alice got to use one last year!
One day that thin brown wall will no longer have its East/West Berlin style Charlie Checkpoints and instead have simple Charlie Cards with a song as catchy as the "M.T.A.". Maybe there is already a good mariachi song for that? Or Texan cowboy lament?