Like his mentor, Oscar Hammerstein III, Stephen Sondheim is a poet of musical theater. Unlike Hammerstein he is a composer as well as lyricist. While his music certainly is indeed unique and memorable, his genius resides in the cleverness of his musical word play. It should therefore come as no surprise that his penchant for witty similes was on display in his very first and for a long time unproduced musical Saturday Night -- for example, the following from that show's title song: "The moon’s like a million watt."
Sondheim also likes to extend his similes, for example, the following from "If You Can Find Me" in another of his lesser known shows, Evening Primrose:
When you wake up with one genius less
If you can find me, I’m here
And I’m free
Free as a bird in a tree
Free as the slippers I wear
Free with a year’s warrantee
Free as air
All of these products and me
All that I ask is a chair that tilts
The Keen Company's revival of Marry Me a Little, a chamber musical created to call attention to some of these Sondheim rarities also included this little gem from "Ah, But Underneath" from the London production of Follies:
"She was smart, tart, dry as a martini."