When concertmaster Natsuko Yoshimoto next takes to the stage, she will be playing an instrument that is rich in both sound and history.

Key points: The violin was built in Milan by master instrument maker Guadagnini in the 1750s

The violin was built in Milan by master instrument maker Guadagnini in the 1750s It is currently held in trust and changes hands every three years

It is currently held in trust and changes hands every three years Valued at $US1 million, it is renowned for its sumptuous sound

Yoshimoto, who performs with the Adelaide Symphony Orchestra (ASO), is the latest custodian of the 266-year-old violin known as The Adelaide, which has been valued at $US1 million.

For Yoshimoto it was a case not so much of love at first sight, but at first sound.

"The most important thing with any instrument you have to feel is instant connection, instant love," she said.

"As soon as I picked it up and played it, the first note I played, which was just an open string, I could tell that wow, this was going to be a journey worth taking.

"It has a lot of dimension to the sound, so that there's a real depth to the sound."

The Adelaide was crafted in Milan, Italy between 1753-57 by renowned luthier Giovanni Battista Guadagnini.

Custodianship is awarded to an Australian musician every three years, and Yoshimoto said she had been "counting the days" until it became available.

"An instrument of this kind of calibre doesn't come your way that easily," Yoshimoto said.

The violin was purchased by the state of South Australia in 1955 and is today held in trust by Ukaria, which was set up by music philanthropist Ulrike Klein.

The violin known as The Adelaide is worth an estimated $US1 million. ( Supplied: Claudio Raschella )

It had been in the custodianship of Perth's Paul Wright before his time ended and Ukaria set its sights on Yoshimoto.

"Her name came up, we approached her and she was delighted," Klein said.

"We are very delighted to have that instrument coming back and being heard by the people of Adelaide."

Instrument becomes 'part of your body'

Having such an instrument in your hands does not guarantee success or dazzling reviews, and Yoshimoto said she needed to find a spark for the relationship to blossom.

"You've got to have that connection," she said.

"It's like part of your body, your limb, you know it's part of you and it's how you express yourself and so it's part of your personality."

The Music Committee of South Australia helped acquire the instrument for virtuoso violinist Carmel Hakendorf in the early 1950s, so she could make her debut in London.

The violin had a richer sound after it was restored. ( Supplied )

Hakendorf performed with it for many years under the watchful eye of the South Australian Guadagnini Violin Trust.

Natsuko Yoshimoto said she counted down the days before she could play The Adelaide. ( Supplied: Claudio Raschella )

Now it has been passed down to Yoshimoto, who confesses she is already in love with all it offers, but also admits to feeling a great responsibility.

"Very sadly sometimes instruments can be dropped, you can fall over, accidents happen, but of course you just have to be very careful," she said.

"Extreme dry or extreme humidity are also not great because it's a wooden instrument — they react, they're very sensitive to those conditions."

Like any centuries-old instrument, it has needed some work over the years.

The violin was returned to Cremona in Italy in 2015 for restoration in the workshop of Eric Blot, an international expert in fine Italian instruments.

It was there that restorer Barthelemy Garnier completely changed the violin's set-up and comprehensively cleaned it, leading to a much richer sound and more power in the middle and lower registers.

Yoshimoto will take to the stage with The Adelaide for the first time on Saturday night for the ASO's opening gala concert at the Adelaide Festival Theatre.