"I'm Afraid the Masquerade is Over" (1938) is one of the great "Golden Age" ballads. The music is by Allie Wrubel, and lyrics by Herbert Magidson. Here's a perfect performance by Sarah Vaughan:
I heard this next tune a few days ago on a PBS channel - "El Dia Que Me Quieras," a classic tango written by Carlos Gardel for the 1935 movie of the same name. The version I heard was a live performance, played by Astor Piazzola on bandoneon. I couldn't find that clip on YouTube, but this one is nearly as good:
Kind of similar? The movie opened in New York in 1935. I suppose it's possible that Wrubel heard Gardel's tune and used the melody as a basis for "Masquerade," knowingly or unknowingly.
Even if you think this is a stretch, these are some pretty great songs!