Oh yes let's all remember 2005 when no one ever looked in the mirror and everyone in big city public transport held hands and sung folk songs on their morning commute.
For the record I have sung songs with a subway car full of people on Chicago's Red Line. Was not during commuting hours tho. Alcohol was probably a bigger factor than the presence of cell phones.
The N train was the "3am Disney Sing-a-Long" after the bar on my friend's ride home to Queens.