'Music is passion, it's shared experience, it's emotional'

"It's going to be a big change for me to leave the orchestra after 44 years, because I have been in a defined role for so long, and to an extent in the public eye," he begins. "Suddenly not to have that will be interesting. I plan not to do anything for a while, as I want to wait and see what it feels like to turn the corner.

"Part of me is looking forward to finding out who I really am as the person who is not part of an orchestra. I'm looking forward to meeting him, for I'm not sure who he is at the moment."

As we chat during a break in rehearsals for the BBC SSO's recording of Saint-Saens cello music with Natalie Clein for Radio 3 and release on a Hyperion CD, he glances over at his beloved cello standing in its battered white case. Decorated with stickers from every country he has toured with the BBC SSO since he joined in 1969 – Greece, China and Taiwan, Germany, South America, Holland – it speaks volumes of a life well travelled.

You can almost hear his unspoken inner turbulence.

Sayer is part of the first generation of men who, since the default retirement age was abolished in 2011, is under no obligation to leave. How, then, did he reach his decision to go?

"I know I don't have to go, and it's been quite a difficult choice. But brave is too strong a word," he says. "I feel I've had a good innings, that I need to find a new life, and that it would be wrong to drift on. There are young people who want a job."

He knows first-hand how it feels to be given opportunities. He grew up in a rough area of South London and after his father died when he was just nine, he was offered a subsidised place at the coveted Christ's Hospital in Horsham, Surrey, where his mother only had to pay £4 a year for his schooling.

"It was a charity school and you went there if a parent died and you had your fees paid. It was the most wonderful experience a child could hope to have," he says. Although he initially preferred painting to playing, he took to the cello like a duck to water when he started at the relatively late age of 15.

He arrived in Glasgow aged 21 after training at the Royal College of Music and met his wife Dee, a psychotherapist who works as a counsellor in Airdrie, when she was a medical student and singing in the then SNO Choir. Following a long friendship they married when he was almost 43 and they have two children, aged 21 and 20.

Sayer joined the BBC SSO as cello number two, which he remained for 11 years before becoming principal in 1980 for 16 years before being asked to step aside and take up the cello number four position.

During the 1980s he was a lay preacher in the Scottish Episcopal Church, and though not aligned to any form of spirituality now he is in a meditation group, and says reflection is an important part of life.

He says he was not upset by the request to move to number four. "I wanted to step aside," he says. "I did the principal job well enough, but the pressure is terrific, and even more so if you feel your playing is not of the power and assurance required of the position. On the front desk you have to play solos, and some of them – such as Brahms' Second Piano Concerto, or Beethoven's Prometheus or Shostokovich's 15th or 1st – are really quite difficult.

"But the opportunity to remain in the orchestra was lucky because there was a gap to move into. That doesn't happen often. Usually when you move from number one you're out."

He acknowledges the management skills required in running an orchestra are "very specific". "Most players are by nature insecure, and if one is upset it can affect the balance of the entire orchestra – which can transmute to the audience," he says. "We know we're really no better than our last performance and that reality is exacerbated every day when you sit with a microphone next to you while you're playing. We are aware there are some crack young players coming up behind us.

"The quality of playing has become a lot higher in the last few years, and we are required to play to a higher standard more consistently than in the 1970s. The orchestra has a much higher international profile. We are competing with the best in the world, and playing at the BBC Proms and the Edinburgh International Festival now – a huge transformation."

When he started out, the orchestra did a lot of studio work where there were strict rules about the number of re-takes. "So studio performances came with all the blemishes included, whereas now our studio work is going out on CD all over the world."

Asked what he hopes will be his legacy, he replies: "Not the CDs, of which I'm in about 40. I'm a great believer in live performance. The CD is artificial, redone until it's perfect. But on a live night, it's not perfect. CDs bring kudos and income, but music is a biological event. Great music taps into the deepest things that you can feel, and you have to be responsive to that. People talk about music as being communication but it's deeper than that. It's passion, it's shared experience, it's emotional and you have to recreate it every time.

"My own musical education depended on records and radio, but live events are important. It's not the real event if it's not coming from the heart."

Despite his high-profile, high-octane career, he is concerned that by listening to music via electronic media, people will lose touch with the "beauty and drama" of live acoustic music. He also worries avant-garde classical music will become trapped in an ivory tower as the focus on recording "liberates" contemporary composers from the need to communicate with a live audience, in a one-off win or lose performance – the immediacy through which Mozart and Beethoven, for example, had to succeed.

His pet project during his time with the BBC SSO was helping to launch the Big Noise schools orchestra in the Raploch, Stirling, in 2008 – an initiative that has encouraged hundreds of schoolchildren in the deprived area to learn to play an instrument. It is also taking root in Govanhill, Glasgow.

Sayers says: "The Big Noise project is not about getting kids to play in middle-class orchestras; it's a social and psychological education. It's about human development. In the countries that most support music education – for example, Finland – the general knowledge of the people is far greater and that is because music helps holistic development.

"There were 50 languages being spoken by the kids at Govanhill, yet the music brought the children together in a way that no other medium can. Big Noise shows that music is below culture and lies deeper in our human consciousness. There is no culture in the world that doesn't have music, yet somehow we've made it middle-class, a bolt-on to our lives."

I wonder if he has any regrets. "I joke about being a dinosaur, only doing one thing all my life. It's too late for me, but I hope future generations of musicians will get more work outside the orchestra.

"There's no doubt classical orchestras all over the world are looking for new audiences. The fact festivals such as Celtic Connections are selling tickets in their hundreds of thousands shows there's a colossal appetite for a varied programme of music. How we can meet some of that audience and persuade them they can get as much joy out of what we're doing continues to be a challenge.

"That said, the BBC SSO has just had its best season yet, with sales and subscriptions up, so I'm leaving it in fine fettle."

As he surveys his beloved City Halls stage before going back to work, he remains reflective.

"Charity schoolboys are conditioned to feeling privileged and grateful all their lives. Having had the pleasure of playing with the BBC SSO for 44 years, I feel doubly, unbelievably blessed."

l Anthony Sayer's final concert with the BBC SSO is Alive With Music: We've Got Rhythm! at the City Halls Candleriggs, Glasgow G1 1NQ, on Sunday 23 June, 3pm. www.bbc.co.uk/orchestras/ events/1553