Is it better to be straightforward or abstract? There are definite merits to both. The latter ensures that the message is clear and unmistakable while also lending it a layer of conviction, only achieved by emotional honesty. The former, though, allows the message to mean anything to anyone and can shield vulnerability from the prying, critical eyes. The conflict between these two lies at the heart of Are You Serious, the eleventh album by indie folk rocker Andrew Bird. A fascinating hit and miss performer, so much of Bird’s output has been filtered through the cerebral and the surreal that…