With this concept album about inner conflict, materialism, mortality and mental struggles, Pink Floyd largely got down to the point, leaving alone “that psychedelic noodling stuff” (guitarist David Gilmour’s words) from their earlier work. Certain rock albums are like the aural wallpaper of suburbia; this is the granddaddy of those, which is why a reggae tribute like Dub Side of the Moon can be easier to appreciate. But a listen with fresh ears reveals the beauty in “Us and Them,” and the overall brilliance of the record’s cohesion. Hear one song and you have to hear them all.