In the 1990s two of the most important contributions to jazz research have been published by scholars with an ethnomusicological background and approach: Paul Berliner's "Thinking in Jazz"and Ingrid Monson's "Saying Something". The paper discusses these two studies and demonstrates how a cross-cultural perspective can help to better understand phenomena such as improvisation as being based on idiomatic constraints determined by the respective genre by applying relevant concepts to the karawitan tradition of Central Javanese gamelan music.