Shel Silverstein was a renaissance man who wrote plays, poems, songs, movie screenplays and cartoons.
One of the songs he wrote was "Sylvia's Mother" for Dr. Hook & the Medicine Show. It was the band's first big hit in 1972.
The lyrics are autobiographical. Shel was in love with Sylvia Pandolfi, who was getting married to another man. The event broke his heart.
In this 2002 video below, Sylvia's real-life mother, Louisa Pandolfi, talks about Shel, her daughter, their relationship and the song. Sylvia also makes an appearance, and shows letters from Shel to her.
This 5 minute sweet/sad documentary piece was directed by Arjan Vlakveld.
One note: one of the drawings shown here is obviously by Arnold Roth (at the 3:40 mark), not Shel Silverstein.
Above photo of Shel nicked from the Artie Wayne blog -- some great reading there!