Relative difficulty: Easy-Medium
THEME: none
Oka (Russian: Ока́, IPA: [ɐˈka]) is a river in central Russia, the largest right tributary of the Volga. It flows through the regions of Oryol, Tula, Kaluga, Moscow, Ryazan, Vladimir, and Nizhny Novgorod and is navigable over a large part of its total length, as far upstream as to the town of Kaluga. Its length exceeds 1,500 kilometres (930 mi). The Russian capital Moscow sits on one of the Oka's tributaries—the Moskva River. (wikipedia)
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There is much that I love about this puzzle: it has a contemporary feel but is well balanced with answers from many different realms of knowledge and many different eras; it's full of unexpected, interesting answers; it has lots of Xs; etc. But there are two things that were disappointing. First, the difficulty level was wildly uneven—it was supremely easy for long stretches, and then there'd be some obscurity like "TIME TRAX" (?) or some oddity like WIGWAG (?) and things would grind to a strange, temporary halt. Puzzle seemed to over-rely on pop culture titles to provide difficulty ("FOXY LADY," "TIME TRAX," "WE R WHO WE R"). Never a great puzzle feature. The bigger problem, however, was that there are two completely terrible crosses in this puzzle—one I got, one I didn't.
In both cases, the crosses are both proper nouns of dubious fame, that cross at a not-completely-inferrable letter. This is the definition of a "Natick" (for a definition of the "Natick Principle," go here and scroll down to the glossary). And this puzzle has two. Firstly: yes, MARIO KART is a major video game franchise, but most adults (not all—MOST) are going to be familiar with MARIO but have No Clue about the strange, un-video-game-sounding KART (and its spelling). And only hard-core crossworders know what the hell the OKA is. The only reason I got this one was that I knew OCA was a South American tuber, so the spelling was probably something else. Now that I look at this corner, I know it's going to be a total disaster for many, esp. many older solvers. Ke$ha song with a title from outer space crossing "SAW II" and L.A. GEAR. That's a whole lot of commercial names in one little place. And WIGWAG is down there too, so, yikes (I had WIGWAG as WAFFLE and then WIGGLE...).
There is much that I love about this puzzle: it has a contemporary feel but is well balanced with answers from many different realms of knowledge and many different eras; it's full of unexpected, interesting answers; it has lots of Xs; etc. But there are two things that were disappointing. First, the difficulty level was wildly uneven—it was supremely easy for long stretches, and then there'd be some obscurity like "TIME TRAX" (?) or some oddity like WIGWAG (?) and things would grind to a strange, temporary halt. Puzzle seemed to over-rely on pop culture titles to provide difficulty ("FOXY LADY," "TIME TRAX," "WE R WHO WE R"). Never a great puzzle feature. The bigger problem, however, was that there are two completely terrible crosses in this puzzle—one I got, one I didn't. 
In both cases, the crosses are both proper nouns of dubious fame, that cross at a not-completely-inferrable letter. This is the definition of a "Natick" (for a definition of the "Natick Principle," go here and scroll down to the glossary). And this puzzle has two. Firstly: yes, MARIO KART is a major video game franchise, but most adults (not all—MOST) are going to be familiar with MARIO but have No Clue about the strange, un-video-game-sounding KART (and its spelling). And only hard-core crossworders know what the hell the OKA is. The only reason I got this one was that I knew OCA was a South American tuber, so the spelling was probably something else. Now that I look at this corner, I know it's going to be a total disaster for many, esp. many older solvers. Ke$ha song with a title from outer space crossing "SAW II" and L.A. GEAR. That's a whole lot of commercial names in one little place. And WIGWAG is down there too, so, yikes (I had WIGWAG as WAFFLE and then WIGGLE...). The other Natick (the one that got me) was SONO / ULANOVA. Again, two proper nouns of dubious fame, but this time, both from the Same General Sphere of Knowledge (the sphere of classical music, broadly defined). That's a huge no-no. It's fine to have all manner of answers in your puzzle, including all manner of oddities and obscurities, but you do not cross unfamous proper nouns 
at an uninferrable letter and you Especially do not do so when both answers are from the same cultural world. It doesn't give the solver a chance. Every solver is ignorant of something, and the beauty of Crosswords is that he/she can save herself from having that ignorance completely derailing the solving experience. This is all to say that I had SOLO / ULALOVA. Obviously ULANOVA sounds more correct now that I see it, but it's not like "L" is an absurd guess, and SOLO seems sooooo much more plausible than SONO (20A: "Dove ___" (Mozart aria)). I mean, it's a *&^%ing aria, and SOLO is a *&^%ing Italian word. Dear lord, if you're going to have a terrible answer like SONO, and your cross is from *&^%ing ballet, at least clue it as a prefix or something. Ugh. This is what happens when you don't take care to avoid this kind of crap—it's what people remember. Actually, a whole lot of people are going to have errors and Never Know. If I'd done it on paper, I would've been blissfully unaware that SOLO / ULALOVA was wrong.
at an uninferrable letter and you Especially do not do so when both answers are from the same cultural world. It doesn't give the solver a chance. Every solver is ignorant of something, and the beauty of Crosswords is that he/she can save herself from having that ignorance completely derailing the solving experience. This is all to say that I had SOLO / ULALOVA. Obviously ULANOVA sounds more correct now that I see it, but it's not like "L" is an absurd guess, and SOLO seems sooooo much more plausible than SONO (20A: "Dove ___" (Mozart aria)). I mean, it's a *&^%ing aria, and SOLO is a *&^%ing Italian word. Dear lord, if you're going to have a terrible answer like SONO, and your cross is from *&^%ing ballet, at least clue it as a prefix or something. Ugh. This is what happens when you don't take care to avoid this kind of crap—it's what people remember. Actually, a whole lot of people are going to have errors and Never Know. If I'd done it on paper, I would've been blissfully unaware that SOLO / ULALOVA was wrong.Please note: I gave you two examples of Naticks today. One got me. One didn't. The point isn't what I, personally, do and don't know. I knew the Ke$ha song and the video game and the tributary, but I can still see that it's going to (unfairly) screw other people up. Objectively, the crosses I have discussed are bad. Cluing on SONO- could've saved the one cross. I might have indicated that MARIO KART had a misspelled word—it would've gone nicely with the "WE R WHO WE R" clue, which did the same.
Bullets:
- 17A: 1958 Buddy Holly hit ("MAYBE BABY") — nice answer, and one that was a joy to uncover, mainly because it had me combing through and humming the Buddy Holly catalog.
- 18A: "Guaranteed relief every time" sloganeer (EX-LAX) — not my favorite way to get two Xs, but daring nonetheless.
- 29A: Letters signifying quality brandy (VSOP) — I know this only from crosswords. See also OKA and ARIE
51A: Rappers' covers (DO-RAGS) — Some rappers' covers, sure. Many non-rappers' covers too.- 42A: The so-called Island of the Gods (BALI) — weird: whenever the Judeo-Christian God or anything biblical is in the puzzle, you never see any of this "so-called" nonsense. You could just put the phrase "Island of the Gods" in quotation marks. "So-called" sounds snarky.
- 3D: Chickens for dinner (FRYERS) — I wanted POLLOS ... because ... of arroz con pollo? I don't know.
- 9D: Eponym of a frozen food (EDY) — don't normally think of ice cream as a "frozen food" (I think more of frozen vegetables or Stouffer's dinners and the like). But, of course, ice cream is indeed a frozen food. And this eponym was very easy to come up with.
