Tasmanian Kelvin Smith pushes piano to top of Hobart's kunanyi/Mount Wellington

After a gruelling 21 hours, musician Kelvin Smith has pushed his 240-kilogram piano across the finish line of the world's toughest half-marathon — the Point to Pinnacle.

"I'm exhausted," Mr Smith said.

"It feels very surreal. I've got a whole lot of emotion around this. I don't know how to contain it all."

Starting from Hobart's waterfront on Saturday, the day before the race, Mr Smith, alongside his support team, pushed his piano to the summit of kunanyi/Mount Wellington, 1,271 metres above sea level.

He arrived at the top on Sunday morning, just minutes before the race's fastest runner.

"If it hadn't been for my amazing support team, I simply wouldn't have made it," he said.

"They were encouraging and smiling and singing and just helping me take the next step. It was phenomenal."

A musical metaphor

Mr Smith founded A Piano of Tasmania five years ago, playing for audiences at picturesque locations around Tasmania.

His piano has been dropped by helicopter on the Gordon Dam wall and has hung from a crane on Hobart's waterfront.

"My whole venture with A Piano of Tasmania has been to just do something crazy enough to bring smiles to a few people's faces," Mr Smith said.

With his "piano to pinnacle" challenge, he hopes to take that impact to the "next level".

"It pushes deeper than a smile to helping those that are going through vulnerable moments," he said.

Kelvin said the challenge was a metaphor for the struggle of living with mental illness.

A critical reminder

Alongside raising awareness and prompting some smiles, Mr Smith hopes to raise $40,000 for suicide prevention charity SPEAK UP! Stay ChaTY.

Charity founder Mitch McPherson said the challenge was "up there" with the most remarkable fundraisers undertaken for the organisation.

"You soon realise that he means business," Mr McPherson said.

He said the challenge was a reminder that everyone had difficult days and needed support.

"That's what we want people to think today, that if they're going through a tough time, put one foot in front of the other and people around you will support you the best they can," Mr McPherson said.

Mr Smith said the public usually saw him at his high point, playing the piano.

A challenge six months in the making

In preparation for the climb, Mr Smith said he had pushed his piano up the equivalent of kunanyi/Mount Wellington 10 times in the past six months.

Using an old piano and bricks — which at one point weighed 100 kilograms more than the weight of the piano he used this weekend — Mr Smith trained on a slope in Kingston with support from physiotherapist Matt Lancaster.

"[It] raised a few eyebrows with the neighbours," he said.

As for celebrating his feat, Mr Smith was not planning a big night.

"Horizontal on a very comfortable mattress — I think that's where the celebration is going to be at," he said.

While Mr Smith has no future piano adventures planned, he is not ruling any out.