Dear Freegigmusic Friend: This website is free for you and always will be. The site was created with the purpose of serving music and musicians like you for free. There are, however, costs of maintaining it. The lyrics to Ave Maria song were taken from Sir Walter Scott's poem The Lady of the Lake and Adam Storck wrote the German translation Schubert used for his song. The person responsible for setting the Ave Maria lyrics in Latin remains a mystery to this day.

I remember the first time I heard the voice of Maria Callas. It was September 1977. I was six years old and an inconsolable Greek media corps was mourning the death of a woman they hailed as the greatest operatic singer ever born. My mother was sad – she loved opera and had a few Callas records on a shelf in the living room.

'Why don't you have a listen?' my mother said. She let me choose one of the albums. Unaware of controversies about the Callas voice, her weight loss, her 'tigress' label, the walkouts, the lawsuits and the soap opera of her private life, I placed the needle on the shiny vinyl in my sister's bedroom, where the turntable lived, and sat down on the wooden floor. I held the record cover in my hands and looked at this strikingly beautiful woman in a white lace dress, holding a parasol, as the crackle of the opening grooves gave way to the orchestral introduction to Casta Diva from Bellini's Norma. What came next was nothing short of a magic spell, which still binds me.

That afternoon was the birth of my lifelong and inextricably linked love affairs with vinyl, with opera and with Maria Callas. She would have been 90 this week. Her recordings are more than half a century old. She has been dead for more than 36 years. And still, every opera discussion forum and message board is dominated by heated discussions about her voice, her art and her place in history. Her CDs continue to be top sellers, issued and reissued yearly. Biographies and documentaries continue to be made. Archives continue to be scrutinised for lost broadcasts. YouTube videos – not just of her, but of most opera singers – continue to be littered with comments about whether she was better in this aria or not. To those who love her as to those who dislike her, she has become the yardstick by which all others are judged.

Ave Maria Schubert Maria Calas

I have no wish to discuss the trivial issues of whether she was really a mezzo with a pushed top or a soprano with an ugly voice, whether the vocal problems that she encountered were due to a lack of technique or her sudden weight loss or whether she was better or worse than another singer. To try to intellectualise how the vibrations of a sound penetrate the ear and speak to the heart would be folly. As true music lovers understand, there is room in the world for infinite interpretations by infinite artists. But there are some to which one keeps returning and which – like every great work of art – hold new and surprising details each time.

Callas popularised and brought opera into more households than anyone since Caruso, making it accessible not by becoming a 'crossover' artist, not by dumbing her art down, but by making it unbearably exciting. Each time I listen to her, I become that six-year-old wondering how it is possible that a human throat can produce so many colours and so many hues within them. The ultimate interpreter of recitative (the half-spoken bit in between arias, duets and the like), she illuminated every word with equal care. She took the vocal fireworks of bel canto and forced them to make sense inside the context of the melodrama. She expended her entire vocal capital each time she sang, instead of safely playing within the margins of the interest.

Her friend and biographer, John Ardoin, once said to her: 'It must be a very enviable thing to be Maria Callas.' She replied: 'No, it's a very terrible thing to be Maria Callas, because it's a question of trying to understand something you can never really understand.' After 35 years of listening, often breathlessly, I have ceased trying to 'understand'. I listen, I enjoy, I gasp, I cry, I let her take my hand like a starry-eyed six-year-old and take me on journey after journey through music.

Happy birthday, Maria.

Five recordings of the extraordinary art of Maria Callas

• This is a perfect example of 'the ultimate interpreter of recitative'. It is a section of the studio recording of Madama Butterfly by Puccini, under Karajan's baton. No aria, no duet, no big ensemble, no conventional or obvious opportunity to excel – just a woman piecing together, word by word, the horrible realisation that her American husband has not returned to be with her, but has sent instead his new wife to take their son away. Expectation and impatience turn to shock and sorrow and ultimately to magnanimity and resolution.

• This trio from Bellini's Norma, recorded in 1955 from the Scala in Milan, shows how Callas used the flaws in her voice to immense dramatic effect. The eponymous heroine here discovers that one of the young acolytes has been seduced by the father of her own children. What follows is an astounding unleashing of emotion, enough to sweep away armies.

Ave Maria Schubert Maria Callas Latin

• Compare the size, volume and ferocity of the voice in the last recording to this – the final stretta from Bellini's La Sonnambula, recorded live in Cologne in 1957. It's a young girl expressing unadulterated joy through impossibly difficult vocal bravura, and it is almost impossible to believe that the same singer could so moderate her voice from heavy to light, from worldly to innocent, from expansive to capricious. The E flat diminuendo (a very high note, held and made to diminish in volume) in the middle of the scene is the stuff of legend.

• The live 1958 Medea in Dallas represents for many the pinnacle of Callas's career. The finale paints the picture of a woman possessed, contemplating infanticide, while the mother within her fights the idea with every bit of her strength. Between 6 minutes 38 seconds and 7 minutes 36 seconds, you will hear almost a minute of perfect opera, from the rejection of her children with the chilling 'Lontan, lontan, serpenti! Via da me. Dal collo mio lontan. Mi soffocate' (Away, away, snakes! Get lost. Get away from my breast. You suffocate me) to the heartbreaking 'No, cari figli, no!' (No, my dear children, no!) when she cannot complete her terrible task.

• Back to where it all started – that 1949 Cetra recording of Casta Diva, which I first heard on the floor of my sister's bedroom – simplicity, unerring beauty of musical line and flawless diction