“I’VE passed this place so many times” says Robert Plant, admiring the giant, subtly lit broadleaf trees that encompass the grassy arena at Westonbirt Arboretum.

“Prince Charles lives around here,” he muses, before crowning a regal performance crammed with surprises with one of his former band Led Zeppelin’s most bullish songs.

“Been a long time since I rock and rolled…” hollers Plant, giving full rein to a set of lungs as familiar to fans of a certain age as his equally enduring contemporary, Roger Daltrey.

It has been a summer evening to savour as Plant, his golden (though greying) curly locks falling onto a red satin shirt, takes us through a 90-minute career spanner.

We get deep, heavy blues (Spoonful, Crawling King Snake) with appreciative acknowledgements to early inspirations such as Howling Wolf, Robert Johnson, Mississippi and Sun Studios.

There are choice cuts from recent work notably the infectious Little Maggie which he playfully describes as Appalachian folk by way of Cornwall.

And there is a raft of dramatically re-worked tunes – with African instruments often to the fore – from his ex-band which, with wilful amusement, he never refers to by name.

After the stomping, metallic funk of Trampled Under Foot, as riveting as it is unexpected, he tells us that the song is from “a previous catalogue.”

Also from a previous catalogue, Black Dog has several thousand intoning in unison “dreams of you all through my head.”

The Rain Song – cripes, I’d forgotten all about that one – is suitably mellifluous as the night-time gently descends upon the arboretum.

Meanwhile, that doyen of world music, guitarist Justin Adams can hardly disguise his joy as he cranks out those meaty Jimmy Page riffs on that corner stone of hard rock, Whole Lotta Love.