"Moonlight Serenade" (Glenn Miller)

My grandmother was a big fan of Big Band.  Especially the music of trombonist/bandleader Glenn Miller.  I remember sitting on her living room floor as a kid and listening as she played Miller's albums, soaking up the sounds of "In the Mood" and "A String of Pearls."  
"That's music, baby," she'd tell me.
I liked the faster tunes, but it was Miller's breakout hit, "Moonlight Serenade" (1939), that really grabbed me the first time I heard it.  I made her stop the album to play it a second (and maybe third) time, just to soak it all in.  
When she asked me what it was about "Moonlight Serenade" that I liked so much, my four-year-old brain was at a loss for words to describe the masterpiece that I'd just experienced.  It wasn't "nice."  Or "pretty."  (Even though it was.)
Then, Gramma put it perfectly: "It's mellow."
Mellow.  Like a fine wine.  Or watching the sunrise on a quiet beach.  It's the best adjective for the so-called "Glenn Miller Sound."
After arranging music and playing for other bandleaders throughout the 30s, Miller formed his own band in 1937 but had trouble selling records and booking gigs because nothing really made his sound stand out.  He ended up breaking up the group just a year later, leaving him depressed and searching for his aural trademark.
When he retreated to New York in 1938, he began playing with new ways to arrange his compositions, and a formula hit him: put the clarinet out front to play the melody, a tenor sax to double the melody an octave below, and then add one more tenor and two alto saxes to play harmony.
That's exactly what you hear on "Moonlight Serenade," and exactly what pulled Miller out of the doldrums and into superstardom.