Sinead O'Connor, Royal Festival Hall, london

Gospel truth from an unpredictable and inventive performer

Sinead O'Connor was never afraid of making a statement. Since shaving her hair in defiance of stereotypes, at the peak of her fame she tore up a picture of Pope John Paul II on television. A decade later in 2003 she announced her retirement, threatening to end a 20-year career which had taken unexpected twists and turns from her early days as an alternative solo artist to traditional Irish folk and reggae. Her collaborations are wide reaching too from Sly & Robbie to her recent duet with Ian Brown on his anti-war song "Illegal Attacks".

On her last tour she bemused audiences by playing solely reggae numbers from her covers album Throw Down Your Arms, having for a long time eschewed the songs of her early career.

Tonight the ever unpredictable artist abandons the Hare Krishna-style dress of recent performances, and instead wears a dark androgynous suit more fitting of a pop star. But most surprisingly of all she embraces her commercial successes, returning to the early hits which first made her a star in the late '80s and early '90s.

Beginning with "The Emperor's New Clothes" from her chart-topping second album I Do Not Want What I Haven't Got, she gets the excited cheers that are just the beginning for her largely crowd-pleasing set. Her band are lively, playing the Irish whistle and soaring fiddle to effect in songs such as the Celtic reggae "Lamb's Book of Life".

O'Connor is also inventive in her performance. In a particular highlight, the a cappella "In This Heart", the crowd is silent and captivated as she begins alone, joined by first the female bassist's voice, then female violinist and finally the male guitarist, all providing richly melodic harmonies. It is beautifully moving.

But elsewhere while she makes chat with the audience, getting the odd laugh for her charming wit, for a singer known for her passion she is oddly distant at times, keeping a downward gaze, or appearing distracted as she looks to her band members or the sound technician. Still, her voice keeps your attention. "Nothing Compares to You" is an undoubtable treat though her voice prefers the lower register and she altogether bypasses the highest notes. But the song she wrote aged 17, "Never Get Old" which builds up to impressive crescendo is swept off to another level by her voice so powerful it causes echoes to ripple through the Royal Festival Hall. The juxtaposition of the acoustic song that follows contrasts beautifully, fragile vocals of truth and justice over her gentle guitar playing. It's one of just a trio of songs from her latest offering Theology, based on Biblical scriptures rich in classical strings. Explaining how to promote her ecclesiastical album she had to speak to the Christian media, she wittily recounts how a small percentage were annoyed at her suggestion that maybe God doesn't want war. She dedicates "If You Had a Vineyard", which quotes Isiah, "to the Christians who think God likes war".

But for all the dissidents, the fans' cries of "I love you" in between songs, proves O'Connor still has the power to captivate and compel.