Exactly 15 years ago, PJ Morton was supposed to be headlining Fair St. Louis as a member of Maroon 5. The weather had other plans. Torrential rain and thunderstorms made the outdoor performance impossible. Morton, who was also building a solo career in soul music at the time, had a different idea. He hopped on Twitter and told his followers in St. Louis to pull up at Lola, the now-defunct downtown nightspot known for live music. “Now I’m known f…