Alice Tan Ridley, Gabourey Sidibe's Mom, Rocks!
Before absolutely owning her 'America's Got Talent' audition last night, Alice Tan Ridley had only a few claims to fame: She's the 58-year-old mother of Oscar-nominated 'Precious' star Gabourey Sidibe, and she's a dedicated New York City subway performer.

"My daughter is a big star, but I'm still pursuing my dream, which is to become a great singer," Ridley said on the show. And sing great she did -- hard-to-please Piers Morgan deemed her the best audition of the day after her showstopping rendition of Etta James' 'At Last.'

Before her popularity explodes, Susan Boyle-style, in the next phases of 'Got Talent,' here's a look at Ridley's terrific subway performances, culled from nearly 100 YouTube selections. Whether she's bopping around and including spectators or simply sitting and letting her voice do the work, Alice Tan Ridley is one seriously passionate, talented performer. Our favorite videos, after the jump!