The aim of this paper is to examine the use of graphic notation in relation to improvisation and indeterminacy in practice. The paper opens with a background context around terms and ideas about improvisation and indeterminate music pioneered by composers in the 20th century. The techniques the author used in the pieces Fluttering (Brondum 2015) and Serpentine Line (Brondum 2010) are examined and discussed in informal interviews with four musicians. The paper closes with a discussion and conclusions gained from the interviews and from working with musicians in the context of using graphic notation as a bridge between improvisation and notated music. Documentation of the author’s practice and research of these methodological and aesthetical issues may be of interest to composers and musicians that work with similar techniques. It may also add to theory by developing the understanding of a composer’s own approach, and in extension, to ask questions on how to develop these theories further.