John Cage was one of the key figures in the musical application of contact mikes and extreme amplification, as exemplified in his work Cartridge Music (1960). Cartridge Music is an early work of live electronic music, in which all sounds are produced by the means of the amplification of very small sounds, primarily using piezo-ceramic phono-cartridges from record players. Performers replace the needle of the cartridges with different twigs, pipe cleaners, springs and other thin objects, to manipulate the objects (by scraping, plucking, etc), and elicit different sounds, which are amplified and sent to the speakers. Cartridge Music has an open form. The score consists of a number of transparent sheets, and the patterns drawn on them provide only the means to determine a time structure. Each performer has to superimpose the transparencies and work out the time structure by observing the ways in which the drawn lines and patterns on the sheets intersect. The choice of objects and means of manipulation is left entirely to the musicians. The phono-cartridges act as contact microphones, used to explore different objects to uncover new sound materials and reveal the unexpected richness of amplified “microsounds”.
Cartridge Music embodies several concerns that, over the following years, would become axiomatic in much experimental electronic music. One of the most evident, as already noted, is the role of amplification in the production and discovery of new sounds. The sound production, moreover, is strongly connected with gestures performed on everyday objects, instead of traditional instruments. Finally, Cartridge Music is representative of a certain DIY approach to electronic systems – in 1960 few could afford oscillators and tape recorders, but everyone seemed to own a record player that could be “hacked” to play this piece. These concerns were all already present in Cage's work before Cartridge Music. As Nyman points out “Cage's Cartridge Music had its roots in his pre-war Imaginary Landscape No.1 (1939) which introduced a number of proto-electronic instruments, and, more relevantly perhaps, in the category of 'amplified small sounds' of William Mix (1952).” (Nyman, 1999, p.90). Indeed, Cage had experimented amplification before Cartridge Music, as in Imaginary Landscape No. 2 (1942) in which both instruments and electronic devices are amplified through contact microphones. And he had already imported “foreign” objects into the concert hall: an early example can be Living Room Music (1940), in which Cage invites musicians to use “any household objects or architectural elements as instruments, e.g: 1st player — magazines, newspaper or cardboard; 2nd player — table or wooden furniture; 3rd player — largish books; 4th player — floor, wall, door or wooden frame of window” (Cage,1940, Living Room Music, Peters Edition); other examples can be Imaginary Landscape No.4, composed for twenty-four performers operating on twelve radios, or Water Music (1952), for a solo pianist using also radio, whistles, water containers, and a deck of cards. But with Cartridge Music especially, Cage pointed out a different way of conceiving electronic music, without using the equipment of the electronic studios, but inventing and adapting portable electronic devices for improvising or performing indeterminate music (Nyman, 1999 p.89). Cartridge Music exerted a profound influence on the younger generation of composers who started making electronic experimental music in the 1960's.
Many concerns embodied by Cartridge Music appear, for example, in one early work of Pauline Oliveros, the Apple Box piece. In this work, Pauline Oliveros (1932-2016) uses wooden boxes in which apples have been stored as resonators for other kinds of objects. Every apple box is prepared with various objects, and it is amplified with contact microphones. The performers are asked to improvise with the content of the boxes.
The material played will always sound via the resonance properties of the apple box, since the contact microphone is attached to it. The apple box together with its contact microphones functions as a kind of filter, amplifier and reverb, giving the different types of material a similar sound colour, resembling, in effect, the resonance body of an instrument, and producing a unity in sound colour similar to that achieved by an instrument, emphasized by the use of contact microphones or electromagnetic pickups (similar to the ones used in the Neo Bechstein, or in electric guitars) for amplification (Van Eck, 2017, p.111).
Thanks to the amplification of contact-microphones everyday objects are turned into new instruments. The amplification enables the production of previously unheard sounds, allowing for an exploration of everyday sounds in the context of the musical performance.