Allison Moorer seduced the lunchtime crowd at WXPN’s Free at Noon concert on Friday — not bad for a woman who noted with considerable humor that she is eight months pregnant.  She said balancing a guitar on her belly was like balancing a 2-by-4 on a basketball, and that while many pregnant women revel in their condition, she had grown impatient with the process. “I wouldn’t change it for anything,” she said, “but let’s get this shit over with.”  She passed on greetings to the crowd at World Cafe Live, Philadelphia, from her husband, Steve Earle. Moorer’s performance can be heard  here.