I was definitely on Pete Muller's wavelength with this puzzle. I started singing the "theme song" after filling in just two of the answers.
The theme clues and answers are:
17A: Loan to a company before it goes public, say (BRIDGE financing).
30A: Spilling out (OVER the edge).
38A: Periods of unrest (TROUBLED times).
47A: Remover of impurities (WATER filter).
And it's all wrapped up at 59A: The starts to 17-, 30-, 38- and 47-Across, collectively (song by Paul Simon).
I'm always happy to see oldies in the puzzle. There's another one at 50A: "__ Song" (John Denver tune) [Annie's]. It's hard for me to think of that one as an oldie...but it is.
In addition to the theme answers, there were a couple of long answers that were g-o-o-d.
3D: Racing feat (Triple Crown).
27D: Lights on posts, perhaps (street lamps). That makes me think of Memory, one of the songs from Cats. I tried to learn it for my last piano recital, but there was a page that was beyond my ability. Maybe next time.
23D: It may be standing (ovation) was a gimme...and it put the V in place for the second theme answer.
I had some major trouble at the crossing of 26A: Lake that is a source of the Mississippi (Itasca) and 28D: Didn't work that hard (coasted). Neither word was particularly difficult, but I had an error at 29D: They may pop up nowadays (ads). Because I had IMs, I was trying to think of a lake that ended in I. Don't know how long I struggled over there. It didn't help that I didn't know 34A: Director Browning (Tod). I only had the T, so I thought he might be Tim...which meant that coasted eluded me, and so did Itasca. And it didn't help that 10D: Formal rulings (dicta) didn't end in an S. Rather than Itasca, I had _TSS_I. Good luck finding a lake that'll fit there.
I'm blogging the New York Sun for Green Genius again, although that will have to wait until morning. I don't solve nearly as fast as Orange, though, so I've spent the better part of this evening solving two puzzles. As a result, I am lacking vigor (6D: effete), so I'm going to call it a night.
Hope to see you tomorrow.