In 1971 Andrew Morris succeeded Brian Brockless as Organist and Director of Music at the Priory Church of St Bartholomew-the-Great, Smithfield, in the City of London.
His work with adult chamber choirs continued and, in 1985, he founded the New Bedford Singers which he conducted for 10 years in concerts in the home counties.
At St Bartholomew-the-Great he directed several festivals, all of which were widely acclaimed in the national press both for the quality of the performances and the originality of the programmes.
The Festival to celebrate The Queen's Silver Jubilee in 1977, sponsored by The Stock Exchange, featured concerts by the New English Singers under Andrew Morris and the London Schubert Orchestra under Brian Brockless performing mostly twentieth century works.
In his festival organ recital, Andrew Morris gave the British premieres of Jubilate (Augustine Bloch), Hvar Litany (Miroslav Miletic) and Triphtogus I (Pal Karolyi) and the London premiere of Games (Paul Patterson), which had been commissioned by the 1977 St Albans International Organ Festival.
As an organ recitalist, Andrew Morris gave regular recitals at St Bartholomew-the-Great during his time there and, at various times, he has appeared as organist at venues such as the Royal Albert Hall, the Royal Festival Hall, St Paul's Cathedral, King's College, Cambridge, Hexham Abbey, Bedford School Chapel and most of the churches of the City of London.
Under Andrew Morris's direction the School's First Orchestra played most of the Classical and Romantic concerto and symphonic repertoire as well as symphonies by Sibelius and Nielsen and new works by British composers such as Paul Patterson and the recipients of the Composer-in-Residence Scheme which Morris set up at Bedford School (with funds from the Maingot Trust), Alan Charlton, Paul Whitmarsh, Tim Watts and James Lark.
With the School Choral Society, Morris conducted many of the major choral works including Bach's B minor Mass, the St John Passion, the St Matthew Passion, Handel's Israel in Egypt and Samson, the Verdi Requiem and Elgar's The Dream of Gerontius to name but a few.
His notable pupils include the international conductor and violinist Andrew Manze, Royal Opera House timpanist and Professor of Timpani at the Royal College of Music Christopher Ridley, composer and choral director Philip Stopford, pianist and conductor William Vann, Paul and Barnaby Smith, CEO and music director respectively of the Voces8 Foundation, counter-tenor Matthew Venner, musicologist and Lecturer in the Faculty of Music of the University of Leeds, Dr Ross Cole and the former England cricket captain Sir Alastair Cook, CBE.
At Bedford School Morris established a Visiting Fellows scheme, made up of advisers to the Music Department and to the Bedford boys, who included Sir Stephen Cleobury, CBE (then Director of Music at King's College, Cambridge), Andrew Manze (then Chief Conductor of the Helsingborg Symphony Orchestra and Associate Guest Conductor of the BBC Scottish Symphony Orchestra), Richard Egarr (then Director of the Academy of Ancient Music), Paul Patterson (then Manson Professor of Composition at the Royal Academy of Music) and Sir Roger Wright, CBE (then Controller of BBC Radio 3 and Director of the BBC Proms).
Andrew Morris has been actively involved in the contemporary music scene throughout his career and was a member of the executive committee of the New Macnaghten Concerts from 1978 to 1984 and chairman from 1981 to 1984.