Christopher joined Christie’s in 1970, after Cambridge, and took over the cataloguing of musical boxes and gramophones, which he developed into a stand-alone subject at Christie’s South Kensington, where he was one of the founder members in 1975. Other subjects that he has covered over the years are Cameras, Scientific Instruments and Antique Tools and Ornamental Turning Equipment.
Christopher left Christie’s in 2001 and became a consultant, his first sale with SAS was the Roger Thorne collection of gramophones and records, in 2011. Since then, under Christopher's watchful eye, the mechanical music and more traditional side of the music department has gone from strength to strength.