Joni introduces the song this way on October 12, 1967 at the Second Fret in Philadelphia:

A short while ago I was in London and, knowing my duties as a songwriter abroad, I was supposed to come back full of all sorts of songs about, you know, being a coloniast and colonial and all sorts of reports on the latest activities of the Queen and everything in my songs. So I did all the usual tourist things and went around Piccadilly Circus in a red double-decker bus with no driver on the top, and finally figured out how to tip a British cabbie without insulting him. It’s hard to figure out ten percent of their money. It’s hard to figure out their money. And I went to Hyde Park and I soaked up all sorts of speeches. Black Power speeches and White Power speeches and Flower Power speeches. And Irish Power speeches. Catholic speeches and Protestant speeches. Nannies and prams and lorries. And wimpies. That’s sort of a hamburger. They don’t think it’s funny but Americans do. One night I took all the information that I had compiled on London, all of the atmosphere that I had compiled, and I sat down to write a song when [unintelligible] said, “Let’s play Monopoly,” and so we started to play Monopoly and suddenly I found that I had moved by drawing a Chance card to Mayfair Place. I was not to pass Go or collect my 200 pounds and there I was sitting and there was a big grand hotel on it and bankrupted me. So Mayfair Place, that’s English Boardwalk. It’s that little blue one on the corner. Yeh. So I had to sit and wait till the game was over so I could join it again, and while I was sitting and waiting I remembered all my British culture that I had been soaking up and I said, “I’ll write a song about England and my friend Marcie,” and it was her flat that we were playing Monopoly in. And Marcie said to me “Where did you live in New York?” And I said, “41 West 16th Street.” She said, “I lived at 37 West 16th Street.” And I said, “No kidding, when did you live there?” And she said, “Well I left in April, no I left in May, June. I left in June.” I said, “I moved in in April.” So we were neighbors there for two whole months, right smack dab up against each other and never met until we went to England. This is a song about most girls who’ve come to New York City…

Joni introduces the song this way in late 1967:

"This is a song that I wrote in London, wanting very badly to write about red double-decker buses and, uh, taxi cabs with running boards, and how to tip an English cabbie (chuckles)--figuring out the percentage. (Strums) And, uh, Hyde Park speakers and flower power a la San Francisco in London. And the Club UFO and the Rolling Stones (strums and tunes). So I was in the middle of the Monopoly game in the London flat and I'd just picked up a chance card that said, "Go directly to Mayfair Place, do not pass go, do not collect 200 pounds", and Mayfair Place had a hotel on it. And so I was out of the game. So while I was out of the game I said, "Well, this is a good time to write my song about London", you know, England, "swings like a pendulum do", and all that. And I sat down and began to write. And the girl whose flat I was staying in was named Marcie, and I'd met Marcie in Toronto--Ontario and I stayed with her in London. And while I stayed with her in London, I found out that she lived next door to me in New York for two months and we didn't even know it. We'd met in Toronto and we didn't know that either of us would ever be in New York. (tunes guitar) So even though this isn't specifically for my friend, Marcie, I took poetic license and borrowed her name. And is sort of a song for every girl who's had to come to NY (strums) and a lot of fellas, too. And it's called "Portrait in Red and Green".