The mystery deepens

Tired and slightly jetlagged we certainly weren't thinking about music and its reproduction as Terri and I got off a Southwest flight and headed through Houston Hobby to our 10:50 Denver connection. But, there it was again. Just past TSA and before the food court. Live music. Rising above the din of travelers was an acoustic guitar, keyboard, and two singers. We couldn't yet see them to verify that it was live, but its sound seemed unmistakable. We stopped and just listened. "Is there any doubt it's live?" I asked, knowing her response. No, of course not. It was as obvious as the night. Just beyond the curtain would have to be four musicians on a small platform playing live music. But, how? How did we know that? What were the cues separating that sound from a recording of the same group? Puzzled, we walked in front to verify the finding. Sure enough, there were the four musicians. Weirder still, every voice and instrument were amplified and playing through a single speaker from Bose. Their Column Line Array. I am half convinced it is not the work of the speaker, but fully befuddled as to what separated that performance from what it was—amplified music—to what I perceived—Live music.