To paraphrase Oscar Wilde, to lose one band member may be regarded as a misfortune; to lose two looks like carelessness. When Tyondai Braxton left Battles in 2010, fans were worried. Although the quartet had started out as an instrumental unit, Braxton’s distinctive pitch-shifted vocals had become the focal point of their acclaimed debut album Mirrored, and with his departure, expectations for the follow up plummeted. They needn’t have worried, as with the help of a few guest vocalists (including none other than Gary Numan), the band’s second album Gloss Drop was more than a match for its predecessor.…