Actually no I had never thought of writing that phrase anywhere - it was a spur of the moment inspiration to add a wee bit of humor and see if anyone would catch it. With your response being what it was, I'm not sure how far to go by way of explanation - you may be joshing me and the following is for nought!
We were talking about your visit to Steinway and learning to play the piano. When starting out many piano teachers give lessons in how to read music and play the notes on a piece of sheet music. If you look a music score there is a variety of notation that represents the music and instructions on how to play it. It takes a while to learn the notes and to that end there are mnemonics to help - short phrases that identify the notes in each register, treble and bass.
Each register is represented by five parallel lines on which notes are written; notes can go higher or lower than the lines ... we'll skip that for now.
View attachment 87790Treble Clef - the Right hand
View attachment 87791 Bass Clef - the Left hand
Let's look at the Bass Clef and it's basic notes:
View attachment 87793
To help remember the bass notes
... on the lines:
Good
Boys Do
Fine Always
... on the spaces:
All
Cows
Eat
Grass
moo !