More than 200 pupils from secondary schools across London were invited to spend the day inside M&C Saatchi and the various creative sector businesses around Golden Square, including Absolute Radio, Clear Channel and Paramount Pictures.
The event was organised by the IPA to highlight the Department for Culture, Media and Sport's creative economy programme, through which the Government aims to provide a framework to support the country's creative industries.
Ceremonies started in M&C Saatchi's offices with a speech by Lord Saatchi, who built the agency with his brother Charles, to assembled ad industry figures. He said that creativity was a force for good in people's lives and the only antidote to disillusionment.
Burnham told the children that getting into the advertising and creative industries was no longer about "who you knew" and working for free.
Burnham said: "We're working with all the industries here to give people more opportunities to work in all these exciting industries that you're going to look at today.
"Because in the past it was a little bit too much of did you know somebody who worked here, or could you afford to work for free for a year, and you had an internship. It was not necessarily what you knew, it was who you knew.
"What these companies are saying here to you...is that they want to give everybody the opportunity to come and work in these industries."
Burnham encouraged them to make the most of their opportunity to get involved with creative businesses.
"Firstly you've got to believe in yourself... that you've got talent...secondly, you've got to find ways of drawing that talent out and that's what this day is all about and why it's so important.
"We [the Government] can help with apprenticeships...and we're working a lot on that but at the end of the day it comes down to you and what you want to achieve."
Burnham also praised the industry for its commitment to widening its recruitment net.
"I think you are actually making a very powerful statement here today, that this isn't an exclusive square, this is a square for everybody, and everybody can legitimately aspire to come and work here and be a part of these industries that have been a big strength of Great Britain for many years in the past but also for many years to come."
Earlier Lord Saatchi struck a more poetic tone in a short speech celebrating creativity, saying its real importance does not lie in economics but in being a "force for good in people's lives".
"We are victims of a drug administered by the Gods to all humans. As people grow older, they grow more disillusioned...The only known antidote to the drug of disillusionment is creativity."
Talking to Brand Republic later, Saatchi said he felt the advertising and media world was about to regain its position as the number one choice for graduates after years of competing with the financial services industry.
Providing decades of perspective from having lead the dominant 1980s agency Saatchi & Saatchi, which as a plc made an ambitious bid for Midland Bank in 1987, Saatchi said he thought "the tremendous 15-year run" financial services have had in terms of attracting graduates was over.
"We said [last night] to [M&C Saatchi's] graduate intake this year, you must have all been very tempted to go into investment banking because it's very glamorous, tremendous wealth etc, so what are you doing in advertising?
"Of course, there was a discussion about the fact that many of their friends did go into investment banking and now are regretting it terribly because it's a very brutal world. So I'd like to think, well they all confirmed this last night, that students who are graduating this year will put the advertising and media world back at the top in terms of where they'd like to work."