Most concerts don’t begin with a water safety warning and a suggestion to watch out for snakes, but Saturday afternoon’s Hey Rosetta! show was no ordinary event.

In fact, it was a first — the introduction of historic Georges Island as a public concert venue.

Aside from a private charity event with Rawlins Cross a few years back, music on Halifax’s answer to Alcatraz has been limited to the bagpipes of Citadel Hill’s 78th Highlanders during the handful of weekends Parks Canada, the island’s guardian, has allowed the public to explore the site and its fortifications.

Given that concertgoers arriving on the Haligonian III were greeted by a tanned crew, clad in fake bustier halter tops, welcoming them to “Captain Morgan Island” and promoting the merry buccaneer’s grog, it came as surprise that on this occasion the grass-covered walls, dark tunnels and shoreline were deemed off limits for the day.

But whatever negotiations were required between Parks Canada, Tall Ships Nova Scotia 2012 and Sonic Entertainment to pull this off, it was worth it as more than 2,700 music lovers got to enjoy a unique outdoor concert experience on one of the most gorgeous afternoons of the summer.

People were still arriving by the boatload as opening band the Lucy Grays took to the short stage under the striped canopy in the main fort’s grassy courtyard. Winners of Live 105’s Battle of the Bands, the Halifax sextet fit the bill rather well, playing violin-augmented indie pop with zest appropriate for an outdoor show under a perfect blue sky.

The Lucy Grays tempted fate a bit with a song about zombies on this site of a centuries-old burial ground, but from what I could see, the only stumbling, shuffling figures present were thirsting for beer, not brains.

“We’re on Georges Island!” exclaimed Ben Caplan as he took to the tented stage, hoping the crowd would share his amazement at being on “this island of seething snakes.”

With his band the Casual Smokers — actual smoking was verboten on the tinder-dry grounds — Caplan drummed up plenty of enthusiasm as the gentle sea breeze blew through his impressive, pirate-worthy beard.

It didn’t take much effort to get the crowd to accompany his gruff blues growl on I Got Me a Woman. The masses even replaced his Smokers during a brief power outage.

“That was amazing! I’m not going to forget that any time soon,” beamed Caplan, before striking up the pounding Euro-hoedown Bird With Broken Wings and the dark lurching folk of Down to the River.

“The snakes are running now!” bellowed Caplan, like a demented St. Patrick.

And he was right, I didn’t see a single one of Georges Islands’ famous black garter serpents.

“Thanks for coming all this way,” said Hey Rosetta!’s Tim Baker with a smile, as the St. John’s ensemble took the stage at 3 p.m. sharp.

When your show is on an island, you have to run a tight ship and with its constant touring, this band is one of the tightest, sailing the afternoon on a sea of singing faces and clapping hands.

Opening with the title track of its Polaris Prize long-listed album Seeds, Hey Rosetta! made the fort’s walls ring with its string-powered chamber pop. Baker’s innate romanticism became amplified by the iron guns and brick magazines.

Offering up a new song, he sang, “Everybody’s doing it” as the band slipped between tempos and moods, a skill Hey Rosetta! displayed in spades throughout its set.

It was especially noticable on the epic Yer Fall, which peaked with frank defiance before a gentle coda, with lyrics supplied in the show’s program for a mass singalong.

There were other uses of the crowd as a choir, for Into Your Lungs’ New Goodbye and A Thousand Suns, making an already communal experience even more uplifting and inspired.

Hey Rosetta! were the perfect choice for this singular union of location and music.

As much as I look forward to future events on Georges Island, I hope acts chosen down the road will be able to suit the spirit of the place in similar fashion.

(scooke@herald.ca)