Aja is as much a jazz record as a pop one, though in its best moments, it’s both and neither. Steely Dan were so expert at fusing genres it’s often hard to say what bit came from where, or exactly which tradition (fusion, R&B, soul, disco, classical) was being mined or reimagined. Because these songs were rendered so seamlessly, it’s easy to overlook how brazen they were. Aja is like driving down a treacherous, cliff-side road in the most luxurious car ever made: If you sink deep enough into that supple leather seat, it is possible to forget entirely about the twists and turns, the threat of looming destruction. It’s possible to forget about gravity entirely.