The Deacon Blue singer said the debate over Scotland was too important to leave to politicians as he joined Yes Scotland chief executive Blair Jenkins in Glasgow.
The two men were with Yes campaigners handing out leaflets outside the city’s main rail station.
Ross said he had always been a “big supporter of independence” and decided at Christmas that he should become involved in the campaign.
“I thought it was something I needed to speak out about,” he said
“It’s a great opportunity missed if we don’t engage at this time, this fantastic, democratic time in Scotland.
“We’ll never go through another time like this where we all have the chance to talk to one another in a good way, a healthy way, and then come to a decision about how to move forward.”
While much of the campaigning has been done by politicians, Ross said those who were not involved in party politics “can be honest brokers” in the run-up to the referendum.
He added: “We’re not trying to get elected. My career doesn’t depend on this and I like to think people can disagree with me and still like my music. I know I get nice messages: ‘I don’t agree with you but I’ll still come to your gigs’.
“I think it’s important to realise this affects us all, leaving stuff to politicians isn’t good. It’s your country, it’s your vote and every vote counts.”
He continued: “A lot of people assumed at the start of the campaign that the No vote was always going to be in the ascendency, because that’s the default position.
“I think a lot of people assumed it would be done and dusted. It’s not. There’s everything to play for, every opportunity. I’ve always thought when it comes to it, people will see this is a real opportunity.”
Mr Jenkins said the Yes campaign’s “numerous and active volunteer network” was now “beginning to move things our way”.
He added: “We’ve had a good weekend, three very good polls for us, that’s very encouraging.
“But what’s more important is what we see and hear from all around the country, because we’re talking to hundreds of thousands of people all across Scotland, and we know the only direction of travel is towards Yes.
“I’m very confident we can produce a majority on September 18 but we will be working really, really hard up till then.”
The Yes Scotland chief executive said they had “literally millions more leaflets and publications to deliver to people” before September 18.
He stressed the “positive opportunities” of independence, arguing: “We would always get the government we vote for in Scotland, so we would get policies that are more in tune with our values and priorities.
“We would have a more prosperous country because we would have a chance to develop an economic policy which is right for Scotland, which we haven’t had for a long time in the UK, and I think there is also a real will to create a more socially just and fairer society in Scotland.
“What I think people are now waking up to is the fact that there are real threats and risks if we stay in UK.
“People in Scotland are really waking up to the extent to which the NHS in England is being privatised, that’s coming up a lot.
“People know if we stay in the UK the austerity agenda, the pressure on public services, budget cuts, and all of that will continue.
“There’s no doubt this is touching a real emotional nerve with people, particularly women, they can see there is a really strong argument on that front for voting for independence.”