The song relates the tale of a young man who instructs the listener to tell his former love to perform for him a series of impossible tasks, such as making him a shirt without a seam and then washing it in a dry well, adding that if she completes these tasks he will take her back. Often the song is sung as a duet, with the woman then giving her lover a series of equally impossible tasks, promising to give him his seamless shirt once he has finished.

As the versions of the ballad known under the title "Scarborough Fair" are usually limited to the exchange of these impossible tasks, many suggestions concerning the plot have been proposed, including the hypothesis that it is about the Great Plague of the late Middle Ages. The lyrics of "Scarborough Fair" appear to have something in common with an obscure Scottish ballad, The Elfin Knight (Child Ballad #2),^[1] which has been traced at least as far back as 1670 and may well be earlier. In this ballad, an elf threatens to abduct a young woman to be his lover unless she can perform an impossible task ("For thou must shape a sark to me / Without any cut or heme, quoth he"); she responds with a list of tasks that he must first perform ("I have an aiker of good ley-land / Which lyeth low by yon sea-strand").

The melody is very typical of the middle English period.

As the song spread, it was adapted, modified, and rewritten to the point that dozens of versions existed by the end of the 18th century, although only a few are typically sung nowadays. The references to the traditional English fair, "Scarborough Fair" and the refrain "parsley, sage, rosemary, and thyme" date to 19th century versions, and the refrain may have been borrowed from the ballad Riddles Wisely Expounded, (Child Ballad #1), which has a similar plot. A number of older versions refer to locations other than Scarborough Fair, including Wittingham Fair, Cape Ann, "twixt Berwik and Lyne", etc. Many versions do not mention a place-name, and are often generically titled ("The Lovers' Tasks", "My Father Gave Me an Acre of Land", etc.)....

Much thought has gone into attempts to explain the refrain "parsley, sage, rosemary, and thyme", although, as this is found only in relatively recent versions, there may not be much to explain. One common theory is that they are the ingredients for stuffing used in many baked poultry dishes.^[3]

Parsley, sage, rosemary and thyme have — like many other herbs — a symbolic meaning that goes back centuries: it has also been known (parsely, sage, rosemary, and thyme) were the main ingredients to an old witches love potion.

• Parsley has been used as a digestant, which should take the bitterness out of certain comestibles. Some medieval physicians used this herb in a spiritual manner.
• Sage is renowned as a symbol of power.
• Rosemary represents fidelity, love, and remembrance and is therefore often used in traditional wedding customs. Rosemary for remembrance.
• Thyme symbolizes courage and thus found its way into heraldry.

Both man and woman in this ballad invoke said powers in naming these herbs: mildness to soothe the bitterness of their relationship, spiritual strength to endure being apart from each other, faithfulness and lastly encouragement, to fulfill the impossible tasks given.

Another interpretation is that the four herbs are traditionally closely associated with death, as well as being used in charms to ward off the evil eye.^[4]

As in most stories concerning impossible tasks set for lovers or suitors, the tasks set forth in this song are probably riddles, and once the riddle is solved then the task can be performed easily. "Plough it with a rams horn, and sow it all over with one peppercorn" could be seen as a sexual reference.^{[citation needed]}

Plague doctors at the time are also thought to have used the herbs to cover-up the smell of death and decay. The herbs were supposedly put in the beak of their costumes.

Parsley, sage, rosemary, and thyme are all members of the mint family, and are documented emmenagogue, contraceptive and abortifacient herbal remedies. Contraceptives were preferred to abortifacients, because utilization of abortion as a birth control method was more risky, and abortions required assistance and/or instruction (McLaren, 1990)....

Vincent Price's experience actually happened to us this past Sunday! Both congregations which normally meet in our building at 9:00 AM and 1:00 PM respectively were having an abbreviated combined meeting at 5:00 PM to allow all those who were participating in the Mormon Helping Hands weekend cleanups following the devastation of Hurricane Matthew to briefly meet together.

   We normally arrive 20 to 30 minutes early anyway, because I really cannot abide being late, but Sunday we wanted to be extra sure. I think we were 45 minutes early; for a true fact we were the very first to arrive!