Darkness has descended on Los Angeles and the sell-out crowd inside the Hollywood Bowl have fallen into a state of reverie. Joni Mitchell, seated in an armchair on stage and tapping along with her walking stick, is midway through performing Both Sides Now, her brooding meditation on love and life.

She is 81 next month and has suffered poor health in recent years so understandably her voice is not what it was. Yet the audience is transfixed, sitting in hushed reverence while witnessing a folk music icon who even in her twilight years has lost none of her power to mesmerise.

That Mitchell, one of the greatest songwriters of the 20th century, is on stage at all is almost miraculous. In 2015 she suffered a debilitating brain aneurysm and had to relearn how to walk and speak. During her recovery she met the American singer-songwriter Brandi Carlile who helped to organise a series of informal musical gatherings at her home, which became known as "Joni jams".

In July 2022 Mitchell stunned and delighted the musical world with a surprise appearance at the Newport Folk Festival, while last February brought her to the Grammys. Her performance that night was arguably the highlight of the awards show and set the stage for her first official concerts in Los Angeles in more than 20 years.

The Hollywood Bowl, with a seating capacity of nearly 18,000, was a fitting venue for such a monumental occasion. Saturday's performance was the first of two back-to-back concerts that quickly sold out.

Despite her health problems, Mitchell was in fine form, giggling between songs, sipping from a glass of pinot grigio and denouncing Donald Trump. Her beret and sunglasses gave the air of hippy chic.

The first half of the three-hour concert featured deep cuts not widely known to even Mitchell's biggest fans. Cherokee Louise, from the 1991 album Night Ride Home, was one such example. However, Mitchell emerged from a 30-minute break with Big Yellow Taxi, which prompted the first singalong of the evening.

Marcus Mumford, Annie Lennox and Jon Batiste joined Mitchell on stage, while Carlile did a fine job helping the show along in the role of MC. A Case of You, from the seminal 1971 album Blue, brought some in the crowd to tears.

Elegiac, poignant, joyous, Mitchell was unmissable. She stood up for the first time at the end of the concert, basking in a standing ovation from an adoring audience. You don't know what you've got till it's gone? Joni Mitchell's fans are only too aware.