Songfacts®:

• This love affair may be one of a kind, but you'll want no part of it. The lady leaves without saying goodbye, leaving just a note on the wall: "I'm leaving you. Know I love you too. I can't stay with you."
  
  According to the song's writer, Joseph B. Jefferson, this really happened to him. A drummer, he was touring with a group called The Manhattans. He was living with his girlfriend, and when he returned home after the tour, found that message on the wall... she was gone.
  
  Jefferson was working for Producer Thom Bell at Sigma Sound Studios in Philadelphia, and two days later, Bell asked him for a song. Jefferson came up with the title "One Of A Kind Love Affair" on the spot, and over the next few weeks worked with Bell to finish the song, the lyric inspired by his heartbreaking turn of events.
• The Spinners had their first taste of success in 1961 with "That's What Girls Are Made For." In 1963, their label, Tri-Phi, was merged into Motown, where they languished, doing more menial tasks than recording. They had a decent-sized hit in 1970 with "It's A Shame," produced and co-written by Stevie Wonder, but it wasn't enough to keep them around. With support from Aretha Franklin, they left Motown in 1972 and signed with Atlantic. Their first Atlantic sessions didn't go well, but when producer Thom Bell saw they were on the label, he asked to work with them - Bell remembered them from years earlier when they came through Philadelphia on tour. Under Bell's guidance, they found their groove, landing #1 R&B hits with "I'll Be Around" and "Could It Be I'm Falling In Love." "One of a Kind (Love Affair)" was their next single, and it also topped the chart, making it three R&B #1s in a row.
• Philippé Wynne is the lead singer on this track, with Bobbie Smith getting two lines ("I never thought about today would come," "She wrote a line or two upon the wall") to provide some contrast. Smith is an original member; Wynne joined The Spinners in 1972 when they moved to Atlantic.
• According to Thom Bell, Philippé Wynne improvised the lines at the end of the song, extending past where he originally planned the ending.