Price had been due to attend the production, accompanied by a prison officer, and even to sing some of his own songs at the performance. But concern whipped up by the tabloids, featuring photographs of his murdered girlfriend, Michelle Slater, along with interviews with her family, led to the last-minute cancellation of his pass from Edinburgh's Saughton Prison.
"I can't defend what I've done. I'm guilty," Price admits. His crime was a particularly violent one, involving rape, strangulation, stabbing with broken glass, beating and attempted gouging out of eyes. "But I've got to get on with my life by doing what I'm good at," he says, "and that is music.
"The tragedy is that someone had to die before I could make this happen. That's a wasted life. Now I want to make sure there won't be two wasted lives."
Aged 35, Price has spent 13 years in prison and will be eligible for parole in two years' time. Talking to this engaging six-footer of considerable intelligence, who is keen to convey a sense of contrition about his abominable act, it is difficult to envisage him as a market trader leading a violent and chaotic lifestyle that culminated in brutal murder on February 15 1984.
His candour is unsettling and disarming. In the past six years he has developed a love of music by attending workshops run in the prison by honours students from Edinburgh University's award-winning Music in the Community course. From having no more than a passing interest in music, he has acquired the composition skills needed to tackle a work of this length.
The opera, two-and-a-half hours long, is inspired by William Horwood's novel Skallagrigg, as well as other personal and mythological sources. It is set in a psychiatric institution and is a story of hope, faith and love that can be discovered and depended upon in times of hardship and disability. These positive qualities are embodied in the mythical figure of Skallagrigg.
"About 10 years ago I went through a very bad time emotionally," Price says. "I actually tried to kill myself. My probation officer was trying to help me understand my situation. He sent me Skallagrigg. The first 50 pages I didn't really understand, but by the end of the first part of the book tears were running down my face.
"It's about individual hope and - no matter how bad things are - how you realise your strengths when you're at your weakest. I can also relate to the bureaucracy and the patient-nurse relationship that exists in a psychiatric institution. I used my guitar to write a song based on the book. It was only three chords."
The inspiration derived from reading the novel was the start of his musical and educational journey. In Durham Prison, where he had made his suicide bid, he became involved with the education service on the advice of the psychologist to whom he was referred. He obtained GCSEs in maths and English but was transferred to Saughton, where, armed only with his guitar and the song he had written, he joined the first Music in the Community workshops in 1991.
Working with members of the Scottish Chamber Orchestra, who were participating in the scheme, and played in last week's opera performance, he started tentative experiments on orchestrating his song. "I felt it was not big enough," he says. "I wanted to add strings. After I
gave a performance in the prison of other songs based on the book, I realised I needed to expand it, and became interested in musical theory. The music then really grabbed me - I could have it played on the cello, for instance, and it could be universally understood by musicians."
Tiffany Hughes, a final-year music student at Edinburgh University, has been involved closely with Price in the composition process. She puts his work in context: "The scoring that's required for a work like this is enormous. For him to do this is a massive achievement, considering that he could not write a note four years ago. And although we've made suggestions about a particular violin, for instance, it's very much his own work."
After the performance, Price remains in prison, but in common with other men who have come to terms with violent pasts, such as Jimmy Boyle and Hugh Collins, he is using his creativity to build a future. He is in the final year of a general arts degree with the Open University, after switching from psychology to music. But what exactly has musical education done for him? "Ten years ago I would have taken the easy option and done nothing - maybe just written something roughly. I don't particularly like spending night after night awake, writing it all down, but I've got the bit between my teeth," he says.
For now, he is restricted to writing songs on the guitar in his 10 foot by six foot cell. But he plans to learn the piano and keep writing in preparation for the day he is released and can make music his life.