There’s a lassitude, an echoing, fading grandeur, in the sound of “Heroes”: its dragging beat; its backdrop of squalls and what sound like wayward radio signals; its lyric, set at the continent’s scarred heart; Bowie’s extravagant, metal-edged vocal; Robert Fripp’s feedback ostinato. “Heroes” is Bowie at his most empathic and at his most desperate, a wish-chant that offers, at best, some tiny regency for the spirit. Bowie, who had once had filled his songs with starmen and calamity children, seems reduced here to a minor scale, despite the talk of kings and dolphins. Any hope “Heroes” offers is meager: we can be better than we are. Only sometimes, and not for long.