Chorale Generator: Interactive Software for AI-driven Music Generation and Analysis

1. University of Arkansas – CSCE Department Capstone I – Preliminary Proposal – Fall 2011 Chorale Generator Anthony Shumate, Kris Whitmire

2. Some Background • Computational music is a very difficult problem within computer science. • It is similar to the problem of writing a story/novel or creating visual art. • There are no set rules and no set formula to writing good music, and musical taste is relatively subjective. • There are however loose rules and patterns used commonly in writing music throughout music history. • Famous composers in history were known for breaking these rules or doing new innovative things in music, but they often did so in an ingenious way. • Having a computer do the same would be one of the biggest challenges in computational music.

3. Problem • We are going to approach the very difficult problem of computational music in a way that would be doable within two semesters of work. • Voice-leading is a technique in music in which you write for several individual parts in such a way that they move together as a whole, creating an underlying harmony. • There are generally stricter rules that govern proper voice-leading techniques. • Voice-leading, while used heavily throughout all classical music, is most heavily used in chorale writing. • Our problem is to create a program that can generate chorales and provide a musical analysis for them. • To insure that the program is interactive and fun, the user will have some influence on the generated chorale. • To make the program more educational, we are going to also provide musical analysis of the generated chorales. • Students, as well as non-students, could make use of a fun, experimental tool that generates music, and learn some music theory at the same time.

4. Objective • The objective of this project is to write interactive software that uses AI to generatively write 4-part chorale excerpts, while also providing Roman numeral musical analysis of the generated chorale excerpts to the user.

5. Related Work • There have been many people within the last 50 years that have explored the idea of music generation using computers. • Stephan Wolfram came across a core discovery that extremely simple rules can give behavior of great complexity. He found this to be during experiments that he conducted during the early 1980's on one-dimensional cellular automata, now call Wolfram automata. These automata are now being applied to music with the process being call WolframTones.1 • Another approach at computer aided music generation, athenaCL, was accomplished by Christopher Ariza. AthenaCL is implemented as an open-source, object-oriented composition tool written in Python. It can be scripted and embedded, and includes several choices for music output. The software also uses computer-aided algorithmic composition (CAAC).2 [1] Ariza, C. 2005. An Open Design for Computer-Aided Algorithmic Music Composition: athenaCL. Ph.D. Dissertation, New York University. Internet: http://www.flexatone.net/ caac.html [2] Wolfram, S. 2002. A New Kind of Science, Wolfram Media. Internet: http://tones.wolfram.com/about

6. Approach • Design and implement two main modular components, the MGE and the GUI. • Music Generator Engine (MGE) – The music generator engine is a software engine that may take as input a musical line from the user via the GUI. Given this input, the MGE will generate a 4-part chorale around this musical line, using music voice-leading rules and logic. If the user chooses to not pass the MGE any input, the MGE will generate a chorale from scratch. The data generated by the MGE, including a musical Roman numeral analysis, will be passed back to the GUI for display to the user. • Graphical User Interface (GUI) – The graphical user interface is an intuitive, attractive interface which allows the user to input musical lines into the MGE with ease. There will be two input methods for the user to take advantage of, with the possibility of a third. The first method is a text based input where the user will type in the musical notes, following a specific format. The second method is a click based input where the user will simply select the desired musical notation and click on the staff where the symbol should be placed. The third method, if implemented, would be a MIDI input directly from an electronic instrument, such as electric piano. The other function of the GUI will be to display the generated 4-part chorale score and Roman numeral analysis once received from the MGE.

7. Use Cases • Input musical line as text • Input musical line using music staff • (Maybe) Input musical using MIDI keyboard • Generate chorale excerpt • Modify AI chorale generation behavior • Display chorale excerpt • Display chorale Roman numeral analysis • Play chorale excerpt • (Maybe) Change music playback sounds

8. High Level Design

9. Risks

10. Status • We are still in the design phase, however we have most of the GUI planned out. The MGE has not yet been fully designed. • Next steps are to begin the first phase of implementing the GUI, and also finish designing the MGE. • By the end of this semester, we expect to be finished with the design phase, and into the beginning of the implementation phase.

11. Team Member Assignments • Given the fact that the project has two main components and is being developed by only two students, the division in team member assignments is perfectly even in terms of both work and importance. • Anthony Shumate – design and implement the MGE, and provide musical knowledge and guidance in building the GUI. • Kris Whitmire – design and implement an intuitive, attractive, and functional GUI.