SIERRA Hull found herself at a crossroads. Having grown up in public since the age of eleven, when she achieved the country and bluegrass holy grail of appearing on the Grand Old Opry radio programme, the mandolin virtuoso, singer and guitarist wanted to produce an album that showcased a direction that was different to the style that had helped her become established.

She was twenty-four, no longer the whizz kid the bluegrass audience had taken to their hearts, and was writing songs that were outside the bluegrass tradition. So she hired a studio, a top recording engineer and a group of hot session musicians and, deciding to produce the sessions herself, laid down half a dozen of her new songs and ran into a storm of feedback.

“When I played the recording to people a lot of them said, 'Wow, this is cool and so different,'” she says down the line from Nashville. “But then other people said I should do this or do that or whatever. I care what people think but you have to do what you feels right for you, what’s honest, and I got to the stage where I didn’t know what I thought and I had to say, 'Whoa, let’s take a step back from this.'”

The resulting album, Weighted Mind, turned out to be very different indeed from what people might have expected. Although the songs were the same songs, it was also very different from the sessions Hull had self-produced, and the group she’ll be bringing to Celtic Connections, she says, might seem a bit strange on paper, being a trio of mandolin, double bass and saxophone.

“It leaves me quite exposed, I think, but in a good way,” she says, adding that the saxophonist, Eddie Barbash, is a keen student of old-time fiddle music and brings a lot of that style of music’s phrasing and tone to her songs.

The spare, stripped-down sound the group creates stems from the involvement in Weighted Mind of banjo master Bela Fleck. Hull’s friend and mentor, bluegrass sweetheart Alison Krauss had suggested she consider working with Fleck as her producer and when Hull played Fleck her original recording his assessment was that it was good … but.

“Bela put his finger on the problem very quickly,” says Hull. “It was supposed to be my record but I’d been so busy admiring what the musicians I’d hired were playing that, as Bela said, I’d left no room for me. After he listened to the recording, he said, can you sing me that song Compass with just you and your mandolin? So I did he said, Now, that’s much more intriguing. I can hear what the song’s about. I can hear the meaning. Let’s make a record like that.”

Hull’s back story is similarly intriguing. At the age of eight she decided that she wanted to play the violin. Her parents bought her one that Christmas but it was a full-size violin and too big for her. So her dad, who had recently acquired a mandolin, suggested she try that instead and since the two instruments were tuned alike, when they got her a smaller violin she’d know where the notes were.

She did eventually get a violin and played it for a while but by this time she had completely fallen in love with the mandolin.

“I’d play for hours and hours every day,” she says. “My dad would push me, just enough, into learning different things every day and then he got a guitar from my uncle, who lived right beside us and played music all day long, and he’d play with me. We played in church and it’s a short step from gospel music to bluegrass, and here I am.”

With her brother also playing guitar Hull was the star turn at local events and concerts around Byrdstown, the small Tennessee town where she grew up. At one gig they supported Mike Snider, a Grand Old Opry regular, and hearing Hull play, he invited her onto the famous radio show. Shortly afterwards, Ron Block, Alison Krauss’s long-time guitarist, heard Hull and told Krauss about her.

“Alison was my biggest hero right from the first time I heard her,” says Hull. “I used to draw pictures of us playing onstage together and the next thing I know, she phones my folks and asks if I can go and play the Grand Old Opry with her. I’d never even met her before and yet there we were playing on the biggest deal country radio show together.”

With Krauss’s encouragement and interceding on Hull’s behalf, the youngster followed her hero onto Rounder Records, the standard-bearer label for bluegrass and roots music generally, at the age of thirteen. Two albums later Hull was an established teenage touring attraction. Then something completely unexpected happened.

An email arrived from the Dean of America’s biggest music school, Berklee College in Boston, inviting Hull to go and study there.

“I hadn’t given a thought to going on to university or college from school,” says Hull. “I’d really set my heart on living in Nashville, where all my heroes lived and which, especially coming from Tennessee, is the music city. I come from a town of about nine hundred people, my parents aren’t wealthy and the idea of moving to a big city like Boston to live, with all the expenses that would involve was just completely alien to me.”

With a Presidential scholarship covering everything, she needn’t have worried about living expenses and again with Alison Krauss’s encouragement, she went off to study, not on the bluegrass course, as might be expected (she specialised in songwriting and music business), and not as a typical student either.

“I had these gigs booked through to the next spring and I thought, they’re not going to like the idea of me going off every weekend to play down in Virginia or wherever, but it turned out that they were okay with that,” she says. “So every Friday I’d grab a taxi to the airport, fly out and play a couple of gigs and then I’d be back, ready to start lessons on Monday morning. It was a bit of blur in the end and I wish I’d taken more time before I went to find out more about what I could get out of the experience. But coming from a small town where life is quite sheltered and everyone has much the same outlook, just being able to hang out with other young people who were serious musicians and came from all over the world was amazing.”

The Berklee experience didn’t bring about the change in Hull’s approach to her music but it did encourage her to express herself as a songwriter and think beyond the bluegrass tradition.

“Not that I’d written a whole lot of traditional-style bluegrass songs beforehand but the songs from Weighted Mind stretched me in a good way and then the more solo approach changed my musical world,” she says. “I worried about whether people would want to hear just me with minimal backing but I feel like I’m giving them honest music. It’s maybe quite dark and solemn at times but I think it can be uplifting too and it offers people an escape from the daily grind, takes them somewhere different for that hour or so we’re onstage.”

Sierra Hull plays the Mitchell Theatre, Glasgow on January 26