Music for solo instrument and electronics creates a special challenge in the concrete and vivid character of the live performer versus the abstract and fixed character of the speakers with their invisible electrical signals. Composers have tried to bring the two worlds together by creating fields of contact between them; Kontakte by Stockhausen is a prime example of how timbral and gestural similarities connect the acoustic and electronic sound material.

Developments in the field of live electronics have made it possible to fuse the two worlds by using microphones and motion sensors together with machine learning and gesture recognition. New connections are created as the electronic sounds may be triggered by the motions of the musician and similarly the electronic part may be able to listen and react to its surrounding.

In plateau eleven in A Thousand Plateaus, Deleuze and Guattari talk about how the movements, colours and calls of the bowerbirds forms an assemblage of heterogeneous components that together constitute a machinic statement. They also describe how matters of expression emerge from such components and give an example of how leaves of grass with the Australian grass finches become a component for passages between assemblages. Similarly, one may regard music for acoustic instruments together with electronic sounds as a special assemblage of enunciation. By utilising the philosophy of Deleuze and Guattari and their concepts of heterogeneous components, rhizomatic connections, and machinic assemblage, one may reconsider the relation between the instrumental and electronic parts as a question of connections between components and passages between assemblages, rather than similarities and interactions between two worlds.

Many years of working with electroacoustic music evoke the question in what sense one can talk about life in music. The question does not concern traces of the composer's life in the work, vivifying performances or musical experiences full of life, but rather the life of music itself.In order to find an answer to the question I examine three solo concertos in the light of the philosophy of Deleuze and Guattari. The concertos, for flute, violin and piano respectively, with chamber ensemble, were composed within the frame of the dissertation and emanate from the ritornello form as found in Vivaldi. The ritornello concept is also present in Deleuze and Guattari, especially in the book A Thousand Plateaus, in which it serves as a collector and transformer of forces and connections that affect its surroundings. With the ritornello as a bridge between this philosophy and the music, I undertake a close reading of the three solo concertos with the philosophy as a companion.With the ritornello and other related concepts in Deleuze and Guattari, such as assemblage, chaos, territorializing and deterritorializing, I force my way past the musical structure in order to uncover the creational forces of music. In the flute and the flute concerto it is about establishing a fragile point in chaos; in the violin and the violin concerto all is centred around the ground, the earth and the territory; and in the piano and the piano concerto it is a matter of a single drawn-out leave-taking. These three moments -- entrance, deepening and dissolution -- simultaneously operate at a large number of levels, and together they form a single large ritornello of musical life.Contemplating music and musical instruments through the ritornello gives several new perspectives on the music and the composing, among them a view of instruments as upholders of different aspects of the ritornello, the composer as a preserver of the creational forces of music, and the musical structure as a network of forces and connections.

Musikstycke komponerat av Fredrik Hedelin.Framfört av Norrbotten NEO på New Directions festivalen i Studio Acusticum, Piteå, 22 maj 2014.

Musikstycke komponerat av Fredrik Hedelin.Framfört av Norrbotten NEO på New Directions festivalen i Studio Acusticum, Piteå, 30 maj 2013.Konsert på Stockholms Konserthuset med Norbotten Neo. Dirgent: Petter Sundkvist. Flöjtsolist: Sara Hammarström. 6 oktober 2013.Inspelat av Norrbotten NEO och Fredrik Hedelin på skivan "Empreintes Digitales". Utgiven av Studio Acusticum, skivnummer SA10.

Musikstycke komponerat av Fredrik Hedelin.Inspelat av Trio ZilliacusPerssonRaitinen och Fredrik Hedelin på skivan "Dedicated to". Utgiven av Phono Suecia, skivnummer PSCD189.