At this point in the new century, it's obvious that pre-World War II popular music has become one of the dominant modes for a generation of young musicians. This can make for some innovative work — that is, if you care about the harmonic sophistication of Tin Pan Alley songwriting. The Brooklyn, N.Y., duo The Two Man Gentlemen Band play their hokum blues and patter songs with verve, but their lyrics are the thing. Gentlemen Andy Bean and Fuller Condon write about overpriced beer, reefer, Franklin Pierce and The Civil War … sort of. “Franklin Pierce” chugs along at an amazing clip, and the lyrics are something else: “When you're all alone and your money is gone / And your family's dead / Sit back and have another drink, Mr. President.” Call it retro if you must, but this kind of empathetic insight is what pop music does best.