Roger Bullivant was that rare being, a free spirit, and a complete original. Before I moved to Sheffield (in 1976) I knew Roger by repute as an authority on Bach, the author of the definitive book on fugue, and as the senior figure in the Sheffield music department, which he had joined in 1949. Thus I found my first encounter with Roger somewhat bewildering. As a candidate for a lecturing post I had expected questions about my musical capabilities. Instead, Roger interrogated me on my travel arrangements, and gave minutely detailed advice as to the best rail connections back to rural Surrey.

Indeed, I rapidly discovered that Roger had a ruling passion besides music - railways. When I arrived as a new lecturer, we became neighbours in Stephenson hall of residence, and Roger kindly allowed me to house my grand piano in his sitting room. There I would practise surrounded by Roger's accumulated worldly possessions. Every horizontal surface in the room seemed to be covered with tottering piles of paper - tattered musical scores, old bus tickets, and copies of the Sheffield Telegraph yellowing with age. Then there were the train timetables: some were recent and even marginally useful, others included battered copies of Bradshaw in which one could have looked up the times of Sunday trains from Munich to Marienbad a century ago. Along the mantelpiece stood a mournful row of oranges, arranged in a progressive state of decay, while outside on the balcony were the rusting remains of an old LNER railway signal.

In the Music Department the students adored Roger, and were awestruck - as we all were - by his limitless erudition. But his lecturing style was liable to render them helpless with mirth. Roger would sit at the piano playing examples culled from his prodigious memory with an LP record wedged between his spare fingers. Transferring this to the turntable, Roger would move from one part of the record to another by unceremoniously jabbing the stylus across the vinyl surface. When replayed, the needle would follow the deep scratch thus inflicted and omit large chunks of music - much to Roger's irritation. He simply could not understand that the fault was his and not that of the record company.

Once one got used to Roger's eccentricities, however, one came to realise that here was a gifted musician with a stupendously well stocked mind. His conducting and harpsichord playing sprang from a profound grasp of every detail of the music he performed. I had reason to be grateful to him when early in my Sheffield career I put myself forward to perform the mightiest of all piano concertos, the Brahms B flat. Fortunately Roger was at the helm, and he steered with impeccable assurance his inexperienced orchestra - and equally inexperienced soloist - through this daunting challenge.

Given his deep understanding of how music works, it is our loss that Roger's lifetime commitment to making music meant that he had little time to write. Perhaps one day someone may publish a collection of his programme notes, masterpieces of their kind, and written with the disarming modesty that was typical of Roger.

Roger's knowledge of the repertoire from Purcell to Elgar was incomparable, as good or better than Tovey's was reputed to be. But Roger was full of surprises. He was anything but conservative, and championed 20th-century and contemporary music - with the Bach Choir and with the University Orchestra. Marvellously learned himself, he was gently subversive, and mocked pedantry of any sort. A confirmed bachelor, he was a great party-goer, and always at the centre of the Department's social life.

Roger was one of the great figures of Sheffield's music, and he will be remembered with admiration and the warmest affection by all of us who knew him, and by generations of our students.

Peter Hill