Get the tone
We are covering such a range of artists here, many of whom have a wide variety of sounds at their disposal, so it’s hard to be definitive about tone. However, the classic guitars (Fender, Gibson) through classic amps (Fender, Marshall etc.) are in evidence throughout, and in general effects are distortion, wah, delay, volume pedal, tremolo and, in the post-funk styles, envelope filters. The key here is that players have a control over their sound (through both technology and technique) so they can respond to the evolving jam context.