One of the first albums that I remember hearing was [Simon and Garfunkel's Greatest Hits], that my brother bought at Baileys's Crossroads (in a defunct shop called Korvette's).
The first song on the album I remember was Scarborough fair/Canticle which was S&G's rendition of the classic English ballad.
For the longest time, I didn't know what the "Canticle" portion of the song meant.
It turns out it was the "song with the song." In the original ballad, Simon inserted several anti-war lyrics(*) as shown below:
...
Tell her to reap it with a sickle of leather
Parsley sage rosemary and thyme
* Generals order their soldiers to kill
And gather it all in a bunch of heather
* And to fight for a cause they have long ago forgotten
Then she’ll be a true love of mine
...
In most cases, when performed live, since S&G both needed to harmonize the main lyrics ... the Canticle portion of the song was omitted.
One of the rare cases of a live performance that I found where the Canticle portion was included was when they performed the song together with Andy Williams ... most likely because there were (3) voices here...
I think the "Canticle" really makes the song!