Taylor Swift looked red hot in her French Connection "Fast Iris" lace dress at the 2012 iHeartRadio Music Festival. Her exact dress is $198 at frenchconnection.com.
If you love the look but not the price, here's another option from the Jennifer Lopez for Kohl's collection. It's a shift rather than a fit-and-flare style but still has a similar feel. Kohl's sent me a sample of this dress and it's much nicer in person. It's fully lined and the exposed zipper detail on the back adds edge. Available in black or red for $49 (down from $70) in sizes 2-16 at kohls.com. Try code FALLFUN for an extra 15% off.