Thirty years ago, Farm Aid was launched to respond to a farming crisis marked by mounting debt, low prices, and soaring interest rates. In 1985, the year of the first concert in Champaign, Illinois, only 2.2m farms remained, nearly a quarter of the farms operating decades earlier.

Little has changed. The Farm Aid concert, which will take place in downtown Chicago on Saturday, is still combating similar issues: the struggles of mid-size farmers to survive in a climate of unpredictable weather conditions, unstable prices, the development and expense of high-tech equipment, seeds, and pesticides, and farm policies they say favor globalized agribusinesses.

“The fight goes on,” says Jennifer Fahy, the communications director for the organization that is based in Cambridge, Massachusetts. “Farm Aid is still here because we continue to see corporate power has the political power which really affects what farm policies are and those policies tend not to favor small family farmers.”

Saturday’s concert at the FirstMerit Bank Pavilion at Northerly Island once again features co-founders Willie Nelson, John Mellencamp and Neil Young, as well as board director Dave Matthews and Imagine Dragons, Kacey Musgraves, Mavis Staples, Old Crow Medicine Show and Jack Johnson, among others. All the artists forgo their typical performing fees and pay their own travel expenses. To date the organization has raised about $48m and Fahy says about 60% of the ticket sales will benefit Farm Aid programs.

What has changed since Farm Aid began is that revenue share is increasing for small and large farm producers (those with sales less than $50,000 and more than $500,000 respectively), but for producers in the middle, sales are plunging. The US department of agriculture reports that between 1997 and 2012, the total number of farms shrunk 6% while mid-sized farms fell 19%. Large farms exploded at 120% – in 2012 alone they were responsible for producing 66% of the food we consume.

Risks for the mid-size farmers are significant, says Jonathan Coppess, professor of law and policy at the University of Illinois college of agriculture and consumer economics in Urbana.

They face mounting costs in technology, seeds, competition from imports, lowering prices and the struggles to remain competitive against the large corporate producers. They are not small enough to participate in the recent explosion of farmers markets throughout the US and too big to compete against the industrialized players.

“The big operators can take advantage of their economies of scale, but the mid-size farmer can really get pinched,” he says.

Farm Aid programs fund efforts to get younger people and military veterans into farming through training and support, enabling them to transition into independent farm owners. With the average age of the American farmer hovering near 60, this is important, especially in order for operations to remain within families. The organization also provides grants to regional programs that support sustainable farming and disaster relief.

There are currently 2.1m farms operating in the US, according to USDA data published this year, and about 97% of those operations are family-owned, responsible for about 87% of all agriculture produced in America. The agency defines a family farm as one in which the majority of the business is owned by an operator through blood, marriage or adoption.

However, many of these operations are contracted to large agribusinesses, relationships critics say create stealth corporate farms whose practices handcuff farmers by forcing them to assume the majority of financial risk.

Farm Aid has been working to shed light on what it says are systemic injustices in this new contract-driven system. A recent success: its work on the 2008 Farm Bill that directed the USDA crackdown on big poultry and livestock producers who unfairly exploit local farmers through iniquitous contracts that keep them below the poverty line, either by forcing them to assume the majority of costs, or by controlling the chicken houses on their land.

However, farm advocates say that in the years since then, Congress has blocked funding for the agency to enforce those rules, while critics say that committee members are influenced by lobbying from companies such as Tyson and advocacy groups such as the National Chicken Council.

Because the mission of the Farm Aid concert itself is also to raise awareness – the organization also receives money from donors as well as fundraising efforts throughout the year – Fahy says more public speculation about the practices in which Americans get their food will help pressure lawmakers to do the right thing.

“Producers are under the thumb of these companies,” she says. “Farmers are living in poverty and not making what they were promised. It’s a system that needs regulation and needs change.”