Tonight’s Gary Barlow concert in London was a star-studded event, complete with red carpet, royals, and quite a few fans.
Once again, Kate showed her fondness for lace overlays. For the evening’s events, she was in a primarily black ensemble; I think we can comfortably call her frock a mini-dress.
Kate went with Zara’s Lace Tulip Dress, now sold out on both the US and Canadian sites, still available on the UK site in extra small and small sizes. 
A tip of the hat to WKW Facebook friends Jennifer and @MrsRegalEyes for quickly locating the dress online.
Zara
Made of 100% polyester, the frock retailed at $99.99 stateside; it is selling at £99.99 in the UK. WKW Facebook friends Ruby and Dress Like a Lady both noted there are also Lace Pants available at Zara.
Zara
No doubt many Kate fashion followers noted she switched from nude hose to black tights, which made sense from a sartorial perspective as well as a practical one, it was quite chilly in London this evening. We are still debating the clutch (black suede, small bow) and heels (black suede, probably a 4″ heel, slim platform) Kate wore; we’ll update things here as soon as we have that information.
We reference the solving of a ‘major mystery’ in the post title because we believe Kate’s black jacket today is the same as that worn the day after the wedding.
Tonight was one of those occasions when the media is given information about the designers being worn; they were told the Duchess was wearing “a Zara dress and Ralph Lauren jacket.” When looking at the photos it is obviously the same jacket; this is a garment that was very much a UFO (Unidentified Fashion Object), it’s nice to finally have an answer on the designer. A commenter left a comment this evening saying she purchased the jacket on eBay this afternoon.
Ralph Lauren Jacket as sold on eBay
Interestingly, it is the second time Kate has paired the Ralph Lauren jacket with a Zara frock, Zara made the blue pleated dress she wore when departing Buckingham Palace after the couple’s wedding.
Kate fashion followers will recognize the rest of the Duchess’s ensemble; she wore her sapphire engagement ring, charm bracelet, and Kiki McDonough Grace earrings.
Kiki McDonough ‘Grace’ Earrings
No one will be surprised to know that both Prince Charles and Prince William were in navy blue suits, the always astute @MrsRegalEyes noted Camilla was elegant in a chocolate-bronze Anna Valentine outfit, the Duchess of Cornwall previously wore the ensemble to the Pride of Britain Awards.
For those unfamiliar with Mr. Barlow, he is part of Take That, a popular band, and a judge on The X Factor. In fact, last night’s and this evening’s concerts are the first solo shows he has done since 1999. Both shows are fundraisers for The Prince’s Trust and The Foundation of Prince William and Prince Harry; Kate was named an official patron of the latter group in October. More specifically, the funds will be used to help those impacted by this summer’s riots, Look to the Stars has more:
The money raised for The Prince’s Trust will support the charity’s UK City Riots Appeal, helping disadvantaged young people from riot-torn areas to rebuild their lives and communities.
The Telegraph
BBC
ellie
Friday 11th of January 2013
What ... i got that dress my friend ordered for me online from UK... Coincident
Mary
Friday 16th of December 2011
A very affordable alternative (it's similar not identical) to this dress is available at Zeller's in Canada through the Alfred Sung Pure line of clothing. I would have posted a link, but there doesn't seem to be any pictures online. I got mine for $39.95 Canadian. There is also a skirt available.
molleeelizabeth
Monday 12th of December 2011
Bought the dress yesterday in size small at the Zara on 5th Ave. in NYC. They also had the skirt and pants. Can't wait to wear it for upcoming holiday parties!
daisy
Sunday 11th of December 2011
Camilla's outfit looks better. This was a miss.
Scarlett
Saturday 10th of December 2011
Kates style really isn't WOW worthy like Dianas was, even for 1980's clothing Diana nailed fashion and when in the royal family dressed right for every occassion. This is cute but meant for someone very slim,tall with no curves and would accessorize with a jacket and belted. Kate did it right here.. I just know that what suites her would not work well on me .
Lili
Sunday 11th of December 2011
I actually disagree that Diana "nailed" fashion. I thought Diana dressed quite badly through the 80's, in clothes that were either too old or too young for her. She didn't know anything about clothes when she started out, she relied on other people's advice from the beginning, and she and they got it wrong a great deal of the time. It wasn't until the 90's, in my opinion, that she developed a style I liked. On the other hand, I've liked the Duchess of Cambridge's style for years. She has a much more natural and relaxed dress sense than Diana did, whatever you think of her choices. Moreover, she wears far fewer high-end pieces than Diana did, she's more comfortable with affordable, non-designer clothes, and that's a positive. Being able to mix, successfully, high and low-end clothes in your wardrobe is a sign of genuine fashion savvy.
Zoe
Sunday 11th of December 2011
She did not dress right for every occassion, one example is when Princess Diana met Princess Grace Kelly, you can see and the commentators were saying that Diana's dress was too revealing and not right for the event. Having said that Diana is not remembered for her fashion but for her charity work. At this moment in time it is the opposite with Kate, she is famous for her fashion and not her charity work.