Anthony Jackson interview:
Q: One increasingly prominent aspect of your playing is a muting technique involving your right-hand palm and either a pick or your thumb.
A...............As for the "palm mute with thumb," that seems to be much older. Around 1972, I began falling heavily under the sway of Latin music, and I became enamored of the old Ampeg Baby Bass. Although it sounded pretty awful in nearly every other context, in Latin music no other bass sound could touch it, and I wanted it. I wasn’t comfortable with the idea of playing an instrument with such a stylistically limited range—or perhaps I should just be honest and say that I was determined to force my instrument to give me the sound of the Baby Bass. One way or the other, thumb-and-palm emerged as a personal technique giving me what I hoped was a compatible and effective sound for Latin music. Over the years, I’ve gotten comfortable with it, and I feel confident using it in non-Latin situations as well, although the peculiar problems of coordination due to the non-standard right-hand position have taken a lot of effort to overcome.
http://www.pgw.com/catalog/catalog.a...2224&Order=165
