The flute in the theme music spells Morse's name in Morse code. Also, it sometimes spells the name of the murderer(!) and sometimes the name of an innocent character, to throw knowledgeable listeners off the trail.
Colin Dexter named his two main characters after his favourite crossword compilers, Sir Jeremy Morse and Mrs. B. Lewis. Some of the other characters and places are named after local streets in Summertown (north Oxford) where Colin Dexter lives: Rawlinson Road (Ruth Rawlinson in Inspector Morse: Service of All the Dead (1987)), Aldrich Road (Phil Aldrich in Inspector Morse: The Wolvercote Tongue (1987)), Hobson Road (Laura Hobson, the pathologist in Series 8-12) and Lonsdale Road (Lonsdale College which features in several episodes).
Ailish Hurley was the bar manager of Chapter's Bar (now the Morse Bar), Randolph Hotel, Oxford. She was a good friend of Colin Dexter and was a continual source of inspiration to him, persuading him to carry on writing the Inspector Morse novels on which the TV series is based. As a mark of respect, he asked for her to be given a cameo role in the final Inspector Morse film, Inspector Morse: The Remorseful Day (2000), where she is briefly seen serving coffee to Morse and Sandra Harrison. Sadly, she died of cancer on 25 September 2005.