A former music teacher with dementia will release a single he recorded with the BBC Philharmonic orchestra, originally improvised from just four notes.

Paul Harvey, 80, composed the piece after being given four random notes to play by his son, Nick.

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 will be released with proceeds split between the Alzheimer's Society and Music for Dementia.

Nick told the PA news agency:

“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.

Nick said:

“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 composition began with the notes F, A, D and B.

Grace Meadows, program director at Music for Dementia, said:

“We are so honored to be a part of this exceptional endeavor and delighted that Paul and Nick have chosen us in this way."

“It is extraordinary how Paul's prodigious talent is still so evident. This is a remarkable example of the power of music for people living with dementia and why we believe music should be part of dementia care."

“We are so pleased that Nick's filming of Paul has led to this performance and single. We hope people far and wide will be as enthusiastic about downloading it as they have been about hearing and sharing the original video."

The single will be released this Sunday on November 1.