Kasper T. Toeplitz is a French composer and musician of Polish origin, born in 1960. He lives in Paris. He has worked with academic research organizations, such as GMEM, GRM, IRCAM, and Radio-France, as well as with experimental musicians, such as Éliane Radigue, Zbigniew Karkowski, Dror Feiler, Tetsuo Furudate, Phill Niblock and Art Zoyd . Citing Giacinto Scelsi and Iannis Xenakis as influences, his early work was mostly written for traditional instruments. He received several prizes and distinctions for these works: 1st prize in composition for orchestra at the festival of Besançon, 1st prize in the Opéra Autrement/Acanthes competition, Villa Médicis Hors-les-Murs in New York, prize Léonard de Vinci in San Francisco, Villa Kujoyama in Kyoto, and DAAD in Berlin. He has also written for his electric guitar orchestra, Sleaze Art. He then integrated computers into his work, via the programming language MAX.

His experimentation with computers continued, in 2003, with the creation of an instrument he calls the BassComputer, an electric bass with 5 fretted strings and 4 unfretted strings, as in the harp guitar. The instrument is intended to be interfaced with a computer. In 2004, he commissioned a piece from Eliane Radigue called Elemental II, which he interpreted for the BassComputer. This was an opportunity for him to set up his own label, ROSA (Recordings Of Sleaze Art). He later commissioned Phil Niblock’s Yam almost may (Touch Records TO59), and Dror Feiler’s Ousia. He also recorded Capture, one of his own compositions, on ROSA (Rosa#2, 2005), as well as ZKT, by Le Dépeupleur, a laptop duet, formed with Zbigniew Karkowski, and which has been together since 1999 (Rosa#3, 2006).

He has also written for dance (Myriam Gourfink, Loic Touzé, Olivia Granville, Emmanuelle Huynh, Hervé Robbe, Artefact, Christian Trouillas, Jean-Marc Matos), as well as theatre; he has always shown a great interest in literature (J'irai vers le nord, j'irai dans la nuit polaire, his first opera, was based on Sylvia Plath's texts, as was Great Expectations on Kathy Acker's texts; Ruine was composed on a François Bon text), and more recently he has developed "combined" pieces, mixing light and/or video images (K_apture, for computer solo, on Dominik Barbier's videos).

In 2007 he created, with Eryck Abecassis and Wilfried Wendling, KERNEL, a computer ensemble devoted to interpretation, live stricto sensu (without any samples or sequences), of electronic music compositions.