Creating improvisations on chord progressions using suffix trees

Technology nowadays takes an increasing part of creativity in live music software such as the improvisation environment. Specifically, implements techniques for indexing and creating improvisations using a given chord progression. It relies on a database that we call a dictionary, storing musical sequences (audio or MIDI) associated with known chord changes. We define an improvisation on a given chord progression x as a sequence obtained by concatenating musical phrases identified with factors of x that can be found in the dictionary. Given a query sequence x and a dictionary D, we present an algorithm that finds an improvisation on x with respect to D. We use the suffix tree data structure to index D and then produce a graph formulation of the problem in order to find a suitable improvisation in linear time, with respect to the length of x.