Since the punk era, rock music has been mostly attitude. But attitudes have shifted, the ambient electronics of DJ culture have seeped in, and the music now seems just as much about mood. Austin newcomers The Glass Family are a prime example. Sleep Inside This Wheel (i eat records, available at reaches for the prog-like keyboard-heavy edginess of Radiohead’s “Kid A” or, to go back even further, Pink Floyd. But the band skirts both pretension (unless you count the Salinger reference) and gimmickry, sounding, if not wholly modern, at least fresh. Employing a nonlinear pop sophistication probably weaned from Shins CDs, the band puts substance and surprise behind its sound, and vocalist Michael Winningham, hanging at the top end of his register, commands a sense of menace that makes the band’s debut seem even more compelling.