I think I now recognize the quality I liked so much about We're Only In It For The Money: I could feel tropes I'd never enjoyed registering and yet I didn't mind. It wasn't like I analyzed it and came away thinking, "Huh, I guess that has a lot in common with other late-60s music, which is funny, since I don't usually like late-60s music." I heard things which immediately felt like I wouldn't like them, except I did.
Bears some resemblance to the first time I realized that by god I could just walk home in the rain without an umbrella if I didn't have one. I'd never paid any attention to the sensation of rain hitting me before; if rain was hitting me, in the past, I was too busy bracing against it. And you know, rain feels GREAT!
That was partially a matter of willpower, of course, whereas here, I don't know what the confounding factor is. I like Zappa's sonic bag of tricks, I think, and his melodies when he makes them manageable enough.
Oh! Right, anyway: this has that same dynamic, except with fusiony rock and whatever kind of music the Grateful Dead play. Always hated them. Really like this.