We've seen variations on this theme in the past, but I'm giving this one the award for the best execution.
The five theme answers are common phrases, each of which contains a metal in its name...gold, silver, iron, tin and lead. The brilliance lies in substituting each metal's two-letter element.
17A: "Shake a leg!" (Get the Pb [lead] out!).
59A: Sound out? (Cast-Fe [iron] alibi). Excellent cluing...once I had the answer, it took me a few minutes to figure it out.
11D: Try to win (Go for the Au [gold]). This one was the theme giveaway for me, although I initially had GO in one square and LD in the next.
24D: Christmas song since the 1950s (Ag [Silver] Bells). At this point, I realized that SIL and VER weren't going to cut it. I went back to 47A: Warthog feature (tusk)...and there was my real aha moment.
28D: Songwriters' home (Sn [Tin] Pan Alley). And with this one, I was on a roll.
In addition to a superb theme and outstanding theme answers, there was plenty of exciting fill in this one, as well as several two- and three-word answers:
20A: Generally (as a rule). A gimme for me, which gave me an edge with the downs in that corner.
40A: Get on (see to).
50A: Lose freshness (go stale). Another gimme. Sometimes you get 'em immediately, and sometimes you stare stupidly for minutes...
54A: Jeer (scoff at).
39D: Expects (waits for). I had enough of the crosses that this one was way too easy.
Things I didn't know:
14A: Minneapolis suburb (Edina). When I went online to download the puzzle, I read about the bridge collapse on I-35. If you haven't already done so, please take a moment to remember those who were affected by this tragedy.
25A: Alternative to Le Bourget (Orly)...the two Paris airports. Have never been to Paris and didn't have a clue.
26A: Sobriquet for Charles V, with "the" (Wise). I thought he was Sage, but there wasn't an element that began with G that was going to work for 28D.
31A: Start of many Arabic names (Ibn). Do I have something wrong here? Because that makes zero sense. I can't think of a single Arabic name that begins with those letters. Okay, here's what Wikipedia says about it. While the ibn/bin prefix is still commonly used in names, its use is declining; in some places, this prefix is only used in government interactions, and in other places it is dropped altogether. Oh...well, of course I've heard of Bin.
Wasn't sure about but ended up getting:
29A: Suddenly changes course (zigs). When I thought SIL/VER was in the theme answer, though, I thought this must be reVERses.
32A: Car driven by Seinfeld on "Seinfeld" (Saab). I never saw the show, but it was either that or Audi. One of the many tips in Amy Reynaldo's book, How to Conquer the New York Times Crossword Puzzle, is to pay attention to last letters of words. In this case, it was unlikely that 18D (clued as "Uncle Tom's Cabin" woman) would end in a U, making Saab the more likely answer. The woman's name was Eliza...and if you haven't bought Amy's book yet, what are you waiting for? It's under $10 but would be a bargain at twice the price!
Some words that I don't recall seeing in a puzzle.
1A: Whiz (maven). A great word, especially since it rhymes with raven, which reminds me of Edgar Allen Poe. Once upon a midnight dreary, while I pondered weak and weary... That aptly describes me right now, although it isn't close to midnight here.
15A: Dimwit (moron). Boy, I've seen my share of them this week. Today I saw a dog tied to a fence with no water while the owner was inside having lunch. I found a bowl and filled it with water from my bottle. The other night at Red Lobster, a dog was left in a Cadillac, out of water and panting uncontrollably. I called Animal Control, who didn't get out there in time. The next day I called to follow up and to report the license plate. They assured me they would track down the owner and issue a warning. Nothing ticks me off more than seeing children and animals being mistreated by the very people who are supposed to be caring for them.
Stepping off my soapbox now...
52A: Ones standing around monuments? (pillars). The best clue/answer in the puzzle.
47D: Kitchen coat (Teflon). This was a close second.
50D: Object of a knight's quest (Grail). 'Tis but a scratch!
5D: Prophet who predicted the destruction of Nineveh (Nahum). Good Bible clue...I especially like the alliteration between clue and answer.
6D: Like old Rome (Imperial). I'm not sure I'd have gotten that without the crosses I had. It didn't come together, though, until I figured out that the two-letter symbol for lead was Pb. Not to be confused with PB & J.
8D: Ticks off (frosts). See comment at moron.
Time to call it a night. Here's the grid...
and I'll see you tomorrow.