Some months ago the RSNO launched its new winter season.

It was going to be special because it would represent the first stage in marking the coming 125th anniversary of the orchestra. That anniversary would not, for complex reasons, be concentrated into a single season, but would be spread over two: the one forthcoming, from October this year through to early summer, and the one around the corner from that, 2016/17.

"And," said my contact in the orchestra office in a private briefing before the official launch, "you've been going on and on for years about when Walter Weller will be returning to conduct. Well, they're all coming back for the 125th anniversary."

By that he meant all the surviving former principal conductors of the RSNO would be invited back to conduct the orchestra during the course of the anniversary. But because the anniversary itself was being spread over two seasons, so too would the visits by the former principals, namely Neeme Jarvi, Stephane Deneve, Alexander Lazarev and Walter Weller. Peter Oundjian, current music director, will still be in post, we assume, and not require a special invitation. I came away from that briefing with unspoken thoughts ringing in my mind: I hope Walter Weller is in the first batch to return because he's not getting any younger.

He wasn't. But, as it turned out, it was academic. Walter Weller died last week and wouldn't have made it anyway. The news hit me like a hammer blow. I was in Cottier's Theatre, reviewing the Glasgow String Quartet, all RSNO players, when the news arrived by voicemail. I went round to see the players, all four of whom had worked with Weller. They had all heard. After the concert, I sloped off home quietly, feeling very sad and reflective, gathered my thoughts and wrote the review, rather more slowly than usual.

I was phoned late that night by The Herald news desk who wanted a chat and a comment in relation to a news item on Weller's death that they were going to run the next morning. I didn't think my comments would make it into the paper: I know just how tight things are late at night. I do remember commenting that his death absolutely marked the end of an era. And for the RSNO it did. Viennese conductor Weller was the last of that generation of Austro-German conductors with whom the RSNO had any significant relationship. His dad had played in the Vienna Philharmonic. Still young, Walter, also a violinist, played in it too. And, still young, Walter became the leader, then conductor, of that most august and conservative institution, and, by association, with Vienna State Opera.

Over the years, through his close association with the RSNO, our numerous meetings, formal interviews, informal conversations and especially on tour and visiting him in his home, we came to know each other well, and were always on great terms. I never tired of quizzing and probing him for the source of the Weller-RSNO sound. Nobody else got that rich, ultra-deep string sound out of the string section. It was as solid as a tank. It was the tradition Weller was raised in, and it was the tradition he reflected in his direction.

How exactly the quality and depth changed when Walter was on the stand could be recognised and described. Explaining it in detail was another matter. A long time ago, one player said to me: "We don't really know how we do it either. It's just Walter. It's in his blood. He gets it through to us. We have total confidence in what he's doing and in the way he's doing it; and it just comes out that way."

Latterly, things changed. Managements changed. Principal conductors changed. I sensed that Walter was slipping down the priorities list with the RSNO. He didn't seem to be here so often. It was, as one principal player put it to me, "a shame; he wants to come." I knew that only too well. Walter had welcomed me into his home, and was a fine host. We talked on the phone from time to time - small stuff and big stuff - but he always asked about any possible return to Scotland and the RSNO.

I had an unforgettable night in Vienna with him, where he wouldn't let me put my hand in my pocket: "this is my city and you are my guest." He asked what I'd like to do. I told him, so we had a great meal and went off on a pilgrimage, culminating in Heiligenstadt at the cottage where Beethoven wrote his famous Testament. That, I will never forget. Nor will I forget Walter, who kept a great tradition alive, constantly sustaining it with his faithful musicians.