It’s an extremely hot day at Hatchlands, a modest stately outside Guildford built in the 1750s with interiors by the neoclassical architect Robert Adam. Standing in 170 hectares of parkland, the building is as pleasing a representation of the English country house as one might conjure, especially at this time of year when blousy clouds are scudding over green fields and the surrounding woods are offering a flash of rhododendron-pink.

Owned by the National Trust, Hatchlands welcomes visitors between the hours of midday and 4pm (3pm in December), 10 months of the year. They come to admire the huge collection of paintings, including Sir Joshua Reynolds’s portrait of Admiral Boscawen, Thomas Gainsborough’s Colonel Alexander Champion and what is believed to be one of two contemporaneous portraits of William Shakespeare, painted around 1610.

They might not have bargained on a lunchtime recital, played on the house’s collection of keyboards. On this day, they will hear a Saxon 18th-century harpsichord, a quick blast of George IV’s piano and a piece played on Marie Antoinette’s pianoforte (set to go on display in the exhibition about the French queen at the Victoria and Albert Museum). Each piece is performed with tremendous spirit by the house’s primary custodian and tenant, Alec Cobbe. A diminutive 80-year-old man of profuse passions, the art restorer, historian, author, re-hanger, interior designer and painter is also a handy pianist.