The Decemberists understand that referencing the past needn’t mean being musically staid and unoriginal. Hence their creakily melancholic mini dramas featuring orphaned chimney sweeps and leg-baring widows draw as much from the fripperies of modern pop as the conventions of old American folk. It’s a curious blend: songs, without exception, are well crafted but more often than not collapse into cloying jauntiness. Only “As I Rise” and “The Soldiering Life” carry enough emotional weight to merit repeat plays. Still, it’s the overall blend, the looming ghostliness, that impresses.