Talk about proof of concept.

Halifax-based filmmaker Andrea Dorfman is debuting her latest feature film, Heartbeat, at the Toronto International Film Festival on on its first Saturday night.

Heartbeat, her third feature and coming 12 years after her last movie, is a comedy-drama about a musician and stars singer-songwriter Tanya Davis, with whom Dorfman has had a long collaboration.

Here’s the thing: Davis is not an actor, something Dorfman knew well enough when she wrote the script for Heartbeat with the spoken-word poet as the lead.

“I didn’t know if she [Davis] could act. I had a feeling that she could, but making a film you need to convince funders,” the filmmaker told Playback Daily.

“I thought if I wrote a [musician] character that was close to [Davis], even though it’s not her story, then it wouldn’t be a stretch for her to fill that role,” Dorfman added.

But much as she felt she was taking a leap of faith in casting Davis for the lead in Heartbeat – a movie where a young woman stuck in a go-nowhere job and personal life finds salvation by returning to her guitar and musical roots after earlier battling stage fright – she wasn’t.

Dorfman and Davis had a proof of concept for Heartbeat.

The creative duo collaborated on a 2010 YouTube video-poem How to Be Alone, which was based on a Davis poem about living life alone.

The video went viral and has had over 6.8 million YouTube views to date.

“It resonated. It hit a nerve with people,” Dorfman recalls.

It also netted the duo a book deal with Harper Collins for How to Be Alone, which features Davis’ poem and Dorfman’s illustrations.

Here was Dorfman’s leverage: a feature film is a costly engine that potentially drives more reliable ancillary revenues like home entertainment and digital revenues, or book deals that don’t cost nearly as much to publicize as a movie launch.

And Davis and Dorfman had a YouTube video sensation and a book deal in place to help convince funders like Telefilm Canada that casting David in the lead was no leap of faith.

“To work on a longer project was a lot of fun. It took our collaboration to a new level. Rather than work two or three days together, we worked for many months,” Dorfman said of the Heartbeat shoot.

Now the theatrical feature will bow in Toronto, before screening as a gala at the Atlantic Film Festival in Halifax on Sept. 12 and travelling the festival circuit.

“Although I make films in a small city with a strong sense of place, to be able to launch the film as far away as possible is the greatest thing,” Dorfman said of the TIFF world premiere. “A film festival is the best launching pad for Heartbeat. And Toronto is the best festival for that,” she added.

Heartbeat, which also stars Stephanie Clattenburg, Stewart Legere, Kristin Langille, Glen Matthews and Jackie Torrens, is produced by Northeast Films, with Bill Niven and Jay Dahl sharing the producer credits.