WHAT makes a songwriter? If your name is Amanda McKeown, perhaps just a night.

“I literally woke up one morning and thought: ‘I’ve always got these tunes in my head – I’m going to try writing one down’,” she says.

Over the next 18 months, what had began as one became the dozen tracks forming Returned From Sea, the forthcoming debut album from Glasgow-based outfit Sister John.

Something occurred in those unconscious hours – and ethereal debut single He Came Down could evoke a sense of angelic magic in the most cool-headed of sceptics – but perhaps something unusual rather than supernatural.

At any rate, those years growing up raking through the vinyl albums of her parents and older brother, her work as a visual artist and painter, her experiences as a young woman playing guitar and singing in other bands and groups, somehow they were all compressed, filtered and distilled into songs which have a casual, unshowy grace and a maturity you more often find in artists with several albums behind them.

When they played a summer showcase for their label Last Night From Glasgow a couple of months back, there was a similar sense of elegance, despite the band having only played a handful of live shows as Sister John.

Simple and lean, songs such as Try To Be Good or recent BBC Radio Scotland Single of The Week Sweetest Moment don’t need fanfare or adornment; they’re good songs. And this band weren’t just relaxed, they were enjoying it, too.

The feeling was mutual. Surprising then, that multi-instrumentalist Jonathan Lilley, violinist Heather Phillips and drummer/viola-player Sophie Pragnell (a schoolgirl musician on some tracks by The Vaselines, says McKeown) came together to perform the songwriter’s work at a regular musicians’ event held at the Tron Theatre.

Initially unsure of whether her future lay as solo artist or as part of a band, McKeown had chosen Sister John for its ambiguity and its “slightly mysterious anonymity”.

“Warren McIntyre, who runs Fox Star Records, also runs the Seven Song Club at the Tron,” she says. “It’s about the idea that seven songs from somebody is the best amount to listen to.

“He’d heard I was writing and said: ‘Why don’t you do that?’ I’d never performed any of these songs to anyone. That’s how I got the band together with Jonathan, Sophie and Heather. So we rehearsed together and did it. And I think the girls, Sophie in particular, were like: ‘I thought this was a one-off!’ But we enjoyed each other’s company and the sound really worked a lot with what I was writing.”

That writing is continuing, McKeown says, with a couple of tracks in the making for album two.

“Hopefully at the launch gigs we’ll make a foray into the new stuff and see how it goes,” she says. “I’m actually quite interested in what comes out. You don’t really know what will happen, where it’s going to take you next. It is an exciting thing.”

Returned From Sea is launched at two consecutive gigs at the Hug and Pint with support from fellow Last Night From Glasgow artists Mark W Georgsson (Sep 14) and Annie Booth (Sep 15).

Sep 14 and Sep 15, Hug and Pint, Glasgow, 7.30pm, sold out.