Grease to Mack Gordon in 7 Steps
- Grease cast includes John Travolta
- John Travolta is one of many artists that recorded It Had to Be You
- It Had to Be You was sung by Harry Nilsson
- Harry Nilsson sang Shuffle Off to Buffalo
- Shuffle Off to Buffalo was written by Harry Warren
- Harry Warren wrote I Know Why
- I Know Why was written by Mack Gordon