Book excerpt: Since 1960, with the advent of musical electronics, composers and musicians have been using ever more sophisticated machines to create sonic material that presents innovation, color and new styles: electro-acoustic, electro, house, techno, etc. music. The music of Pierre Henry, Kraftwerk, Pink Floyd, Daft Punk and many others has introduced new sounds, improbable rhythms and a unique approach to composition and notation. Electronic machines have become essential: they have built and influenced the music of the most recent decades and set the trend for future productions. This book explores the theory and practice related to the different machines which constitute the universe of musical electronics, omitting synthesizers which are treated in other works. Sequencers, drum machines, samplers, groove machines and vocoders from 1960 to today are studied in their historical, physical and theoretical context. More detailed approaches to the Elektron Octatrack sequencer-sampler and the Korg Electribe 2 groove machine are also included.