Powerhouse new touring drummer Anika Nilles wasn’t the only woman onstage with Rush in Los Angeles Sunday night. During the band’s Fifty Something Tour opener at Kia Forum, singer-songwriter Aimee Mann emerged from the wings in a long white dress as Geddy Lee and Alex Lifeson slammed into “Time Stand Still.” Mann sang her ethereal part on the choruses, marking their first-ever live performance of the song together, 40 years after she sang on the studio version.  As they played, with new touring