Pivotal scents that changed the industry. This is a chemist perspective of what was "pivotal" and this information comes from the book, Scent and Chemistry by Orloff, Pickenhagen and Kraft. An excellent reference book for anyone interested in fragrances.
Fougere Royale - Houbigant's perfume was the first use of synthesized coumarin to create the fougere or fern smell from lavender, oak moss and coumarin.
Guerlain Jicky - still in production today and due to its complex mix (linalool, rosewood, bergamot, lavender, sandalwood, civet, vanillin) is often considered the first modern perfume. The innovative use of synthesized vanilla from pine wood (1874) which made possible an inexpensive source of vanilla for perfume was the innovation that allowed Jicky lead the way.
Chanel No. 5 - 1921 for the first overdose of aldehydes (three different aldehydes at 10%) in a fragrance. Chanel No. 5 is the most successful perfume of all time.
Caron Nuit de Noel created by Ernest Daltroff in 1922 popularized the use of low amounts of quinolines for a warm leather base, the blend called "mousse de saxe" that gave inspiration to many other leather fragrances such as Cuir de Russie, Bandit, Caleche and more leather based fragrances to come.
Eau Sauvage (1966) by Edmond Roudnitska for Dior was innovative for the use of Hedione (1962) as a stand alone ingredient which is now used in this manner throughout the perfume industry.
Drakkar Noir (Guy Laroche 1982) is pivotal for its use of overdose Ambrox (amber) together with 10% of Dihydromyrcenol (lemon/lime/ lavender/fresh). Dihydromyrcenol was already used in Azzaro Pour Homme.
Cool Water (Pierre Bourdon 1988) was the first fragrance to use Dihydromyrcenol in a fougere formula but in such high (20%) concentration and has inspired many others from this use.
Farenheit, 1988(Jean Louis Sieuzac) was inspirational with its addition to a Grey Flannel reject formula the chemical MHC (methyl heptyne carboxylate). This note combination has been often used and is now unavailable as MHC and replaced with Viloettyne or Undecavertol due to restrictions of use of MHC. Farenheit formula also used 25% iso e super and was one of the first to pioneer this chemical as well.
Escape by Calvin Klein (1991) and L'Eau d' Issey Pour Homme were inspirational for their use of Calone in higher quantities to create a watery, aquatic trend in fragrances. Calone inspired a big list of users for an aquatic category.
Angel Thierry Mugler for its use of Maltol (Veltol) for a creme caramel sweet note contrasted with patchouli. Angel is the only perfume to move Chanel No. 5 off its first place chart in sales in France.
Declaration by Cartier 1998 by Jean Claude Ellena pioneered the early trend of iso e super at 35% for transparency in combination with vetiver and other wood ingredients. Declaration formula was an inspiration for many other fragrances to follow that have used from 30% - 75% of perfume for Iso-e -Super for strong cedar, expansive woods, vetiver and incense type compositions - Encre Noir, Incense Jaisalmer, Incense Kyoto, Terre d' Hermes, Ecsentric Molecules etc.
I'm sure I left out many pivotal fragrances but to read more I refer to the book: Scent and Chemistry by Phillip Kraft.