Five and a half thousand people brought their blankets, chairs, cushions and picnic baskets to the concert, themed a ''European Picnic'' to mark the support of the Delegation of the European Union in staging this year's event as a centenary gift.

''It's called a European picnic so all our music comes from Europe - it's a bit like the Eurovision song contest, except that everyone is a winner,'' conductor Guy Noble explained to the crowd.

And like Eurovision, there were costumes too. Among the thousands sporting Akubras, fedoras, bowler hats and baseball caps, were smatterings of traditionally dressed Europeans.

Hungarian Zsofi Summerfield was one. The 15-year-old diplomat's daughter wore a traditional skirt as she roamed the grounds with Canberran Domonkas Szabo, 14. The pair perform with a local Hungarian dance group, but this time the day was about listening.

And skipping and playing. Children rolled in the lush grass, ran between groups, some played backyard cricket and one girl retrieved her errant ball from a rose garden in the official residence of the Governor-General.

But no amount of traipsing through garden beds was going to faze the Governor-General; Quentin Bryce was thrilled to see so many families in her backyard.

''It's lovely to feel the atmosphere here and it's uplifting, and especially gorgeous to have families, children, have the little ones here on picnic rugs,'' she said. ''Children make this place come alive.

''I love music more every year of my life and it's such a beautiful Canberra afternoon and it's a joy to share these lovely gardens with the Canberra community.''

The community came out to enjoy the company and surrounds, all accompanied by the music of Bizet's Carmen, Hummel's Trumpet Concerto, and much else.

The Montgomery and Singer families, neighbours from Nicholls, strategically placed their picnic blankets to the side of the stage with room for their three pre-school-aged children.

''You've got beautiful grounds and it's something you don't see every day or hear every day,'' Andrew Montgomery said.