Watch the The Basics online guitar lesson by Chris Buono from Funk Fission
A cool way to add a percussive element after thumb slapped notes is to incorporate what I call a finger smack whereby you literally smack the strings with your fret hand. This is an essential technique to add to your percussive sound library since it’s the only way to get any kind of percussive sound right after you do a thumb slap.
The smack-action mostly focuses on the lower strings (sixth, fifth, and fourth) though you’ll surely hit all the strings. To make things easier on the eye when looking at all this on paper, you’ll notice I use “FS” to signify the finger smack and only the bottom three strings are notated as seen in Fig. 1 of the chart.
At first, the pick hand/fret hand coordination might be a little tricky, but in the words of Axl W. Rose you’ll need “just a little patience … yeeeah-eah.” Finally, be sure not to smack so hard that you ghost fret any notes and activate pitches—this is strictly a percussive endeavor folks.