An 80-year-old former music teacher, who now suffers from dementia, has stolen the nation's heart with his incredible musical improvisation. 

A video of Paul Harvey shows him improvising a piece of music around four notes, selected at random by his son, Nick.

Since then, the BBC Philharmonic Orchestra has recorded an orchestral arrangement to accompany Mr Harvey's performance - creating an incredibly moving piece that is intended to show the healing power of music.

Mr Harvey's family said it was an "old party trick" for the teacher and composer to be able to improvise song with only four notes.

For his viral rendition of 'Four Notes', Mr Harvey was playing with the musical notes F, B, A and D. 

Music has long been thought to allow for self-expression and recognition, even long after diagnosis with dementia. 

Mr Harvey's incredible composition and performance is testament to just that.

The clip was shared on Twitter and went viral, with more than 1.6 million views.

After it was broadcast on the BBC, the philharmonic orchestra got involved and now a single, entitled Four Notes, will be released with proceeds split between the Alzheimer’s Society and Music for Dementia.

Mr Harvey's son, Nick, said: “It has been such a crazy rollercoaster ride over the last few weeks.

“It’s amazing for dad at this age, but also amazing for the charities. It’s a win-win for everybody.

“Dad has got a twinkle in his eye again, a skip in his step because of the fact that his music is resonating with people, and people are touched and moved by his story.

“It makes him happy, it has given him a new lease of life and it is such a wonderful thing to behold.”

He first asked his father to improvise the tune as a way to cheer up him one day.

He added: “He was pretty low. When dad plays piano he transforms. It is wonderful to watch.

“I remembered an old party trick he used to do when I was a kid. The first time I saw it he was teaching a jazz masterclass in a summer school.

“He composed this incredible piece of music on the spot.

“Everyone rose to their feet, rapturous applause and my heart swelled with pride. For everyone watching, it was magic.”

The single will be released this Sunday on November 1.