"a pioneering work" is a correct and usable phrase in written English.
You can use it to describe an innovative or ground-breaking achievement, such as a book, piece of art, or scientific study. For example, "This photographic exhibition is a pioneering work that pushed the boundaries of photography as an art form."
The music for the third section, Varèse's "Poème Électronique," is a pioneering work that now sounds like Space Age flatulence.
While "Soprano" is considered a pioneering work in the theater of the absurd, Ionesco preferred the term "theater of derision".
On its publication in 1962, The Golden Notebook was celebrated and reviled as a pioneering work of female emancipation.
I suspect that "The Dinner Party" will eventually find its niche as a pioneering work of post-modernist decorative art.
Published in 1938, this last book was a pioneering work, which revived interest in the English baroque architecture movement.
Yet the book was a pioneering work, making it possible for subsequent royal biographers to write with an honesty and intelligence which hadn't always previously been employed.
Her collaborative research on British consumers, The World of Goods (1979) with Baron Isherwood, was a pioneering work of the contemporary anthropology of consumption.
In 1910, a Berlin physician, Dr. Magnus Hirschfeld, published a pioneering work on transsexuality and articulated a relatively new modern definition of gender.
In 1964 Diana's Interior Design: A Penguin Handbook was published, a pioneering work decades before the popularity of TV makeover programmes.
The film that emerged (now a Criterion Collection release) is a pioneering work of the documentary movement that came to be known as cinéma vérité (after Morin's translation of the Soviet filmmaker Dziga Vertov's phrase "kino-pravda").
In 1893 the encyclical Providentissimus Deus ("The Most Provident God"), now outdated but originally a pioneering work, defined in fairly broad-minded manner the principles on which Catholics should interpret the Bible.
