Slightly atypical and not so gory as many other gialli films, but stylish enough and pretty interesting with a great soundtrack by Gianni Ferrio.
The opening of the film was interesting and unusual with the main characters presented for us with their role names as in actor credits, and
with the most famous Tchaikovsky piano concert blaring out at us and then turning into a cool progressive arrangement of it by Ferrio.
A young woman is stabbed to death when she walks through a park in Bergamo, Italy and after some police procedure work and court-room
sequences a middle-aged man are sentenced to life in prison, but then an identical murder occur, and that means ....

A 17 year old girl, Francoise Pigaut (Carole André) is molested and stabbed to death when she walks in the park, and eye-witnesses points
out a TV-personality, middle-aged Alessandro Marchi (Giancarlo Sbragia) as the killer, as he was seen escaping the crime-scene. He's married
to Maria (Ida Galli) and his daughter Sarah (Wendi D'Olive) was a school-mate to the dead girl.
The victim was stabbed to death with a stiletto knife and she carried a LP with Tchaikovsky's Piano Concerto.

Helmut Berger plays a young rich man, Giorgio, with a tortured soul (didn't he always portrait fucked-up guys?) who has a sexual relation with
Sarah, plays the piano (or cembalo?) and listens to Tchaikovsky's Piano Concerto. Red herrings are thrown at us.
The lawyer of the accused, Giulio (Günther Stoll) has a sexual relation with Maria Marchi, and she seems' mentally strained too. Red herrings.

This Blu-ray and DVD edition is presented in widescreen 2.35:1 and with either an english or an italian audio mono DTS-HD MA with english
subtitles. Extras are:

An audio commentary with Alan Jones and Kim Newman, a Booklet with texts, Murder in B-Flat Major: an essay by author Troy Howarth about
this film and about the gialli genre in general, 27 minutes, 2016), Mad Dog Helmut: An interview with Helmut Berger (17 minutes in english, 2016),
A Butterfly Named Evelyn: interview with actress Ida Galli/Evelyn Stewart (54 minutes in italian with english subs, 2016, what a nice lady),
Me and Duccio: interview with Lorella De Luca, wife of Duccio Tessari (8 minutes in italian with english subs, 2016), promotional gallery, italian
and english theatrical trailers