What is "the old Joanna"?

Search: "the old Joanna"

Why: In Pat's favorite song "I Don't Feel Like Dancin'" by Scissor Sisters:

But I don’t feel like dancin’
When the old Joanna plays

Answer: It's a piano! It's from Cockney rhyming slang:

• stairs - "apples and pears"
• look - "butcher's hook"
• wife - "trouble and strife"
• pianner / pianna - "old Joanna"
  

I don't know.

Source: Wikipedia, Yahoo! Answers

The More You Know: Scissor Sisters members are named Jake Shears, Babydaddy, Ana Matronic, and Del Marquis. Lol. This is "I Can't Decide," my favorite song by them: