The tuba is more than 70 years old and was stored in a barn loft after the war
When Guernsey was occupied in June 1940 more than just weapons of war were brought into the island by the German occupiers.
A famous picture shows a marching band making their way up the Pollet and into the High Street.
Geoff Domaille remembered seeing this band play outside the Duke of Richmond Hotel and in 1960 came into possession of several of their instruments.
He said, "they were in a loft in an old barn" when he brought them in 1966.
Geoff explained that the instruments were brought into the island by Pioneer Battalion 15 from Leipzig.
As well as marching the band would play at various locations around St Peter Port to entertain both the locals and soldiers stationed in town.
The band played around St Peter Port as entertainment for locals and troops
When the BBC's A History of the World campaign came to the Guernsey Museum at Candie Gardens Geoff brought along the tuba from his collection.
It was made of brass and silver, though Geoff admitted 65 years on from the Liberation it was "quite tarnished".
Geoff was not sure how much the instruments he had were worth but he said: "I had quite a high offer for the instruments in 1980 but I couldn't part with them as I feel somewhat attached."