We consider as multi-level scenario a description of a temporal structure (e.g. a chords progression) upon several level of hierarchical organisation. In particular, to model a multi-level scenario, we use a phrase structure grammar.

In order to test the benefits of using multi-level progressions, we have generated improvisations using two music generation methods :

• A base generation model taking only the chord progression level of the multi-level progression into account. (a simplified version of ImproteK)
• Our extended generation model using all the information from the multi-level progression (ie. the chord progression, the functional progression and the sectional progression).

• Multi-level scenario generated by the grammar :

• Memory for melodic improvisations: Thriving from a Riff - Charlie Parker

• Base generation model :

• Extended multi-level generation model :

• Multi-level scenario generated by the grammar :

• Memory for melodic improvisations: An Oscar for Treadwell - Charlie Parker

• Base generation model :

• Extended multi-level generation model :

• Multi-level scenario generated by the grammar :

• Memory for melodic improvisations: Thriving from a Riff - Charlie Parker

• Base generation model : No improvisation could be generated with the base generation model since no diminished chord appeared in the memory

• Extended multi-level generation model :