13 January 2016 Last updated at 22:15 GMT
Edward Hardy, who has dementia and lives in a care home in Wookey, Somerset, played for decades but had not touched the keyboard for nearly 25 years.
But, staff at the home said when he started playing again he could play "amazing tracks to a ridiculous standard".
His old bandmates David Payne, 67, Arthur Rice, 66, and Ron Foster, 88, got in touch for a reunion. Clinton Rogers reports.

Undefeated Rigondeaux had to call off a fight with the Liverpool boxer in March because of visa issues.
The Cuban, 35, became WBA champion when Carl Frampton opted to fight for a featherweight title rather than defend his super-bantamweight belt.
"It's been my childhood dream to be the best in the world," said Dickens, 25.

The party is not happy that it was only allocated 25 seconds of airtime which was aired a month before polling day.
The Electoral Commission and the BBC agreed that to qualify for an election broadcast a party has to stand a minimum of 12 candidates in at least six constituencies
The Workers Party said this rule was "effectively putting a price tag on political airtime and also ensuring that the larger, better financed, parties can perpetuate the political circus without serious challenge or alternative views being aired".
The party said it plans to meet with both the BBC and the Electoral Commission after polling next Thursday.
A 93-year-old man who recently rediscovered his love of playing the piano has been reunited with his old jazz band - more than 25 years on.
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Britain's Jazza Dickens will fight WBA super-bantamweight title holder Guillermo Rigondeaux in Cardiff on Saturday, 16 July.
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Members of the Workers Party have held a protest outside the BBC's headquarters in Belfast to highlight what they believe is a lack of coverage given to smaller parties during the Assembly election campaign.