Les Claypool plays slap-style bass, as opposed to picking or plucking the strings of his instrument. Claypool was inspired to play slap bass after seeing Stanley Clarke and Louis Johnson use the technique on their own instruments. Slap bass is played by slapping the desired string or strings with your free hand while using your other hand to move up and down the neck to press the individual frets for the notes. This makes the instrument sound different than when a bass is played by picking or plucking at the strings. Claypool typically uses three fingers to depress the individual frets, though most bass players only use two.
Various bass guitars are utilized by Les Claypool during his live performances. This depends on what song he is playing as well as what musicians he is playing with. Typically, Claypool uses one of six Carl Thompson bass guitars, most of which feature six strings and a fretless guitar neck. The absence of frets on Claypool's bass makes it easier for his fingers to slide down the neck and create different sounds and noises. Claypool sometimes uses a Kramer 8-string bass, which features an aluminum neck, during his live performances.
The whamola is an instrument that is often played by Claypool in lieu of the bass guitar. This instrument is played by striking the single string with a drumstick while using his other hand to press down on the various frets. The tension of the string can also be controlled, which affects the pitch of the instrument.
Audio effects are also utilized by Les Claypool to add more depth and tone to his music. Audio delay, distortion and sampling are all used by Les Claypool on a regular basis during his live performances. Specific pedals include the Tech 21 SansAmp Bass Driver DI, the Line 6 DL4 Delay Modeler, the Line 6 DM4 Distortion Modeler, the Korg Toneworks AX300B and the Boomerange Phrase Sampler.