When I am unhappy with a painting, I typically paint over it at some point. 
This can lead to fortuitous results.  Moreover, I would never want to waste a good surface. But if the surface is not worth saving, then bad paintings might
just end up in the trash. 
I have a friend who had a really bad day and dragged several canvases out to the garbage. When she returned to the garbage bin with her last batch of canvases to throw away, all of the trashed canvases were gone!  She never had the satisfaction of throwing out her bad paintings because they were stolen from the garbage bin.  Now those canvases which she detested might exist forever.  Perhaps the thief will paint over them, or salvage the stretcher bars.  But my friend will never have the satisfaction of laying the paintings to rest. This is stolen art at its finest.

I saw a beautiful tree today on Alvarado Road.  The lines of the tree were easy to see because the tree stood on the edge of a hill.  Behind the tree was mostly blue sky.  The tree looked like a bold charcoal drawing on a blue paper.  I imagined someone drawing the tree onto a blue sky with fat charcoal.  This brought me to the comparison of trees and drawing.  One can look at a tree or a drawing and immediately take in their form.  Compare this to music.  Music is largely linear, in that it takes place over time. Although there is a vertical aspect to music (chords, simultaneity), you pretty much experience music over time with elements such as intervals and melody.  Movies, too, are linear.  Well, a tree or a drawing you can experience instantaneously.  Except that . . . what you see is the result of something linear.  The tree grew over time.  The drawing was created over time.  In fact, the lines comprising the drawing reveal a history of the artist's hand movements.
Maps are cool this way too.  They represent any amount of territory that could take hours or days to cross.  Yet our eyes can take in a map in a moment. 
When I used to memorize music, I always had a visual map of where I was on the page. This was not particularly relevant to the music itself and might explain why I enjoy painting so much.