Considerable research has been made into the harmonic properties and playability of woodwind multiphonics, while the utility of string multiphonics has received far less attention. In recent years, however, there has been an increasing amount of interest in the topic, and several publications have been devoted to acoustic guitar multiphonics. Primarily written for non-guitarist composers, these studies range from the scientific to the practical. Variously, they describe the sonic qualities of the multiphonics, discuss methods of performing them, or examine their spectral content and morphology. Until now, published research into guitar multiphonics has been limited to the acoustic guitar and has examined only its three lower strings. In this study, we analyse multiphonics on all six strings of the electric guitar and present a catalogue of harmonic aggregates on strings 3–1. We test these multiphonics on five different guitars and examine their response to three commonly used analogue effect pedals (compression, overdrive and distortion). In order to precisely indicate the spectral components and harmonic nodes, we have used the Extended Helmholtz-Ellis JI Pitch Notation (HEJI).