GOT a taste for country pop/rock with four part harmonies, early Eagles/ Crosby Stills and Nash?

Got to be at Devonport Guildhall on Wednesday when upwardly mobile London four-piece AHAB arrive ahead of their 22-date Australian tour in March.

Last seen in Cornwall supporting Bellowhead on tour and prior to that at Port Eliot Festival and the Watermark in Ivybridge, these guys have been hailed by Radio 2's Simon Mayo as 'the real deal' and whispering Bob Harris as 'sheer class'.

The band consists of four singer/songwriter guitar players, who were working as a couple of duos before one pair got the call to go to Nashville.

Callum Adamson, son of Big Country main man the late Stuart Adamson, explains: "Dave (Burn) and I put out a record that was somehow picked up by the guy who owns Tootsies in Nashville and he invited us over to play a residency during the Country Music Awards period, back in 2009. Millions of artists would have killed for the chance."

Not wanting to trail out there as just an acoustic duo, they wheeled in Seebs Llewellyn and Luke Price as a foursome and went down a storm. On their return they decided to stay together as an item, but had nowhere to play.

"One night we were drunkenly coming home from the pub and we starting singing in four-part harmony," remembers Callum. "To our amazement loads of people stopped to listen.

"We tried it again when we were sober and realised we were on to something."

Basically there had never really been a good harmonising British country band before.

"The first time of busking we raised £80 in 45 minutes, which is incredible when you have no money. We took to the streets in East London and attracted crowds so big we decided to put up a gig on YouTube. The one we happened to film was where the police arrived to move us along as the attendant hordes were stopping the traffic."

The YouTube footage was spotted by the organisers of Cropredy Festival and the lads soon found themselves playing to 15,000, just before headliners Bellowhead.

"Bob Harris was standing next to me for the whole set – then afterwards asked us if we'd like to do a session for his show.

"That was in 2010 and basically we haven't stopped gigging and touring since. I doubt whether the four of us have spent more than three days apart."

Callum loves the creative process – they are constantly writing new songs – and the demand for shows. Now thirtyish, he has been in bands since he was 13. He moved to Nashville at 17, only to return home when his dad died in 2001 to help support his mum and sister.

"My dad was in one of the biggest bands to come out of the 80s and as a kid I thought it was awesome that he was on stage and that those earnings bought the football boots.

"But by the time I was starting to be interested in music, he was slightly jaded by it all and anyway I wasn't interested in his opinions, he was so old!

"Now all my favourite bands come from before even his time!"

One, The Eagles, are a band which create strong opinions either of love or loathing.

"I hope that's what we do, too. I like bands that provoke strong reactions either one way or the other – I don't like milkiness."

He says the music they do is just for fun – lyrics are unashamedly about girls and thinking either too much or not enough.

"It's certainly not to be over-analysed. Once you start talking of music 'breaking new ground' it all goes to pieces."

Just for fun or whatever, it's their superior song-writing skills, consummate musicianship and seductive four-part harmonies that make AHAB so fine.

This show is one of a handful to test out material for their forthcoming debut album and a warm-up for their Australian tour. Tickets are £5 from ahabofficial.com or slightly more at the door.