Quote from Fender Site:
"Jaco was legendary for coating his fingers with fried chicken grease before going on stage, in order to lubricate his strings. However, some of Jaco's friends have disputed this legend, saying it is just a myth."
Also from Jacop.net
"While on Weather Report tours, or on the Joni tour, I never saw
Jaco purposely coat his fingers with chicken grease before going
on stage. Mostly after soundcheck the band munched backstage.
Jaco at some point would change the strings on both his basses,
which he did before every show. There were times when I heard him
say to a group of inquiring minds around him at the time, that leaving
chicken grease on his fingers helps....laughing heartily and playfully.
The truth is, there were times he left chicken grease on his fingers."
I've tried this and it also takes away some of
the string noise you hear with roundwounds...
That was the Inspiration for the song "The Chicken"
Everytime I open my case it smells like KFC!!!
