The solo instrument that produces the melody in the title music is a theremin. It was invented by Russian scientist Leon Theremin and was first demonstrated in 1920. It predates the modern synthesizer by about 40 years, but its uniqueness stems from the fact that it is the only instrument that is played without actually being touched. Its electronic circuits are controlled by two antennas, left and right of the instrument, toward which the player moves his or her hands. The closer the right hand to one antenna, the higher the pitch. Similarly the proximity of the left hand to the other antenna controls the volume. The theremin has a range well in excess of eight octaves, and is capable of all kinds of strange effects. These sounds have been put to use in science fiction and other films including Alfred Hitchcock's Spellbound (1945) and Robert Wise's The Day the Earth Stood Still (1951). This unique instrument has also been used on The Beach Boys' song "Good Vibrations." The late Clara Rockmore was the theremin's greatest virtuoso, and the instrument and its inventor were profiled in the documentary Theremin: An Electronic Odyssey (1994).
In an article in the 19 March 2011 edition of the Radio Times listings magazine, producer Brian True-May was quoted as saying about Midsomer Murders: "We don't have ethnic minorities involved. Because it wouldn't be the English village with them. It just wouldn't work. Suddenly we might be in Slough. Ironically, Causton is supposed to be Slough. And if you went into Slough you wouldn't see a white face there. We're the last bastion of Englishness and I want to keep it that way. I'm trying to make something that appeals to a certain audience, which seems to succeed. And I don't want to change it." He was suspended for these comments, perceived to be racist, which provoked a lot of discussion in the media, with opinions polarized in favor or in opposition with the policy. He was later reinstated but it was announced that he would step down as producer after the 2011 series had finished.
A large number of actors have appeared in more than one episode of Midsomer Murders, sometimes as characters in an episode after their first incarnation has been horribly murdered. The first time this happened was with Richard Cant and Elizabeth Spriggs, who appeared in the episode Dead Letters (2006) nine years after they had both been murdered in the episode The Killings at Badger's Drift (1997). They played close relatives of their previous characters and D.I. Barnaby commented on the uncanny resemblance. Other actors who have "come back from the dead" in this way include Felicity Dean and Anna Massey.
The trivia items below may give away important plot points.
As of 2011 there have been 200 murders in Midsomer, including 12 from poisoning (one from a tropical frog), 9 drownings (one in a vat of soup), 6 burned to death (one in a straw effigy) and even 4 villagers killed by bow and arrow.