The Difference Between Ingredients, Notes, and Accords

I come across lots of folks in the fragrance community who confuse fragrance ingredients (aromachemicals), notes in the note pyramid, and accords. I wanted to write about my take on these three after learning a bit about perfumery and looking at formulas; hopefully this can be useful to people first starting to get deeper into fragrance appreciation, or complete beginners in terms of perfumery.

Ingredients

Fragrance ingredients come in two forms: natural essences which have been extracted from flowers, herbs, spices, woods, resins, etc, and aromachemicals which have either been isolated from their natural source (i.e. coumarin from tonka beans), or synthesized in a lab. Ingredients are not the same as notes, though they can be included in the note breakdown. For example, if a fragrance contains rose absolute, even a tiny bit, it is most likely going to be in the note pyramid. However, if a fragrance contains dihydro myrcenol, a synthesized aromachemical, most likely it is not going to show up as a separate note in the pyramid.

Notes

Notes are, in essence, simply marketing tools. They let you know as a consumer what the fragrance is going to smell like. This is why aromachemicals usually don't make it onto the notes listing. Most people don't know what "alpha ionone" or "phenethyl acetate" smell like. It makes more sense to list "iris" or "honey," even though the fragrance does not contain any actual iris or honey essence. Because of this, not a lot can be gleaned about the actual chemical makeup of the fragrance from the notes listing. It is also not possible to know by just looking at the notes how "natural" the fragrance is. Any "note" or scent that occurs in nature can be approximated by aromachemicals.

Accords

Accords are the building blocks of fragrances, and fragrance ingredients in turn are the building blocks of accords. A single-note fragrance might contain only a single accord, but most fragrances contain at least two or three. And accords in turn can be made up of many, many naturals and aromachemicals. Accords aren't usually talked about in the fragrance community since there is really no way to tell how many accords went into a particular fragrance; in other words, how the perfumer organized the fragrance's creation. But they are arguably the most important part of learning how to make fragrances: knowing how to compose them and learning how to combine them effectively into a fragrance that makes sense.

Other Thoughts

Because note listings are a combination of naturals and accords, it is very difficult to tell just from looking at the notes what a fragrance will smell like. Is the rose note a small amount of rose absolute in another accord just there to round it out? Or is it a huge accord in and of itself that dominates the fragrance? Even two accords that are attempting to capture a similar "note" can smell nothing alike. Conversely, an abstract accord that is not seeking to recreate anything in nature (e.g. Baccarat Rouge 540 Eau de Parfum's "burnt cotton candy" accord), can be expressed wildly differently in two different note listings, even though they smell very similar. Cloud Eau de Parfum doesn't share even a single note with BR540 but is almost a dupe for it.

Hopefully this is slightly educational for some of you; I know I would have found it very useful a couple of years ago. Let me know in the comments if you have any other insights regarding ingredients, notes, and accords.