Mathias Heise

Jazz is an improvisation-centered music tradition that emerged from African American communities in the early 20th century. It blends blues feeling, ragtime syncopation, European harmonic practice, and brass band instrumentation into a flexible, conversational art. Defining features include swing rhythm (a triplet-based pulse), call-and-response phrasing, blue notes, and extended harmonies built on 7ths, 9ths, 11ths, and 13ths. Jazz is as much a way of making music—spontaneous interaction, variation, and personal sound—as it is a set of forms and tunes. Across its history, jazz has continually hybridized, from New Orleans ensembles and big-band swing to bebop, cool and hard bop, modal and free jazz, fusion, and contemporary cross-genre experiments. Its influence permeates global popular and art music.

Classical accordion is the use of the concert accordion (often a free-bass “convertor” accordion or Russian bayan) as a fully fledged classical instrument in solo, chamber, and concerto settings. Unlike folk, pop, or musette traditions, the classical accordion employs a free-bass left hand capable of single-note lines and full polyphony, allowing true four-part counterpoint and organ- or keyboard-like textures. The instrument’s bellows enable uniquely elastic phrasing and long, organ-like sustains, while registrational changes supply a palette ranging from reedy delicacy to orchestral weight. The repertoire spans baroque and romantic transcriptions, 20th‑century modernism, and a rich body of late‑20th and 21st‑century works written specifically for the instrument, frequently exploring extended techniques (bellows shakes, air-button noises, key/percussion effects) and, in contemporary settings, electronics.