As the second official BBC Theatre Organist, in succession to Reginald Foort, he achieved considerable broadcasting time during and after World War II.
He also put out programmes with other artistes, for instance, Robinson Cleaver and his wife Molly (who played organ and grand piano), Stephane Grappelli, Oscar Grasso, Gladys Ripley and Isobel Bailey.
When the BBC briefly switched to broadcasting only light music in September 1939, MacPherson played up to twelve hours per day, also filling in with announcements and programme-notes whilst the organisation hastily evacuated its staff from London to various locations around the British Isles.
At the end of the war, the BBC purchased the Moller from Foort and moved it to the Jubilee Chapel, Hoxton, East London, where it remained until 1963.
The instrument is now installed in the Pasadena Civic Auditorium, having spent periods in Hilversum, Holland, and in a pizza parlour in San Diego, California, US.