Thunderous applause heralds the band and, before we know it, Runrig are rocking the Castle: not really surprising, as they must own the ramparts now after playing there six times.
Their trademark Celtic rock is the perfect soundtrack as the light seeps from the sky and the Castle starts to glow.
And the music is an energetic mix of old and new to keep the audience entranced. Even the weather is on our side – dry, mild and not too windy up in the ginormous Tattoo stands.
With the new album, The Story, the focus of the evening, its tracks make up about a third of the play list.
First up is Onar, then The Years We Shared, before the classic festival favourite Pride of the Summer with its “beat of the drum” rallying call.
One of the stand-out moments of the evening is the album’s title track. The three big screens etching the poignant romance of The Story on the Hebridean landscape as they perform.
Fittingly in this old military fortress, Rise and Fall’s symbolism for war’s lost generation is intense, channelling the energy of the evening.
The moments of drama are not all planned and later a gull swoops around the Castle and soars away as frontman Bruce Guthro’s voice cuts through the night in Rocket to the Moon.
With The Story being Runrig’s last studio record, the elephant on the esplanade was “would this be their last Castle gig?”.
Guthro faced it with a frank answer: “We don’t have a damn clue what the future holds”.
For the fans, the message was clear: “We know this: that not one chapter, not one word, could have been written without your dedication”.
And in the 1980s classic Every River, the line “there’s no way without you” is sung passionately to those fans.
The Story inevitably looks to the past, as Rory Macdonald explains as he talks about writing the songs with his brother Calum.
He recalls the days when the band started out in Skye: driving a transit van on single track roads to dances and promising their dad they would give it a couple of years before they got proper jobs.
Where the Rivers Run then has the feet tapping and the bodies swaying – just as the Runrig music did at those Skye dances 40 years ago.
The drumming face-off that followed was fast and furious, intensified when the guitar and the kaleidoscope of Celtic designs join in.
Of course, the familiar Runrig finale – and Loch Lomond – is what we are all waiting for and, with an esplanade-full choir giving full voice, it is the fitting ending for a perfect outdoor gig.