Automatic Timbre Mutation of Drum Loops

Acknowledgements As this work is an abstraction of previous work, I must use this space to extend thanks to those people that have helped me in development the algorithm as it exists thus far. First and foremost, I must credit the knowledge and guidance of Dr. Juan P. Bello, whose tutoring in the use of the MATLAB coding environment and amassed knowledge of subject material had aided me through the various phases of the project's design and implementation. In particular, Dr. Bello's previous work on onset detection (Bello et al., 2004), and rhythm modification of drum loops (Ravelli et al., 2007), had made this project possible. I must also thank the NYU Music Technology Program, which has brought me further into sound construction than I knew possible only two years ago. I had originally applied to the program thinking that I would continue working in the field of electronic dance music production, however through the guidance of Kenneth Peacock, Robert Rowe, Dafna Naphtali, and Richard Boulanger, I have since expanded my scope to include the interests of research in Music Information Retrieval (MIR) and Digital Audio Effects (DAFX). The NYU Music Technology Forum, which generally meets on a bimonthly basis has been a constant source of inspiration for the project, and has provided essential feedback on the various decisions chosen throughout the algorithm's development. I would also like to extend special thanks to Melissa Czajkowski, Liana Eagle and Ernest Li, for their considerate critique and thoughtfulness throughout the project. Finally, I must thank my parents for making such an opportunity possible. Abstract The presented algorithm demonstrates a method by which a percussive loop is automatically segmented into its constituent parts, which are then classified and appropriately resequenced to match the components of a second loop, which undergoes the same process. The two loops are then synthesized together, component by component, and output is presented as 1) a unified .wav file, 2) individual slices (also output as .wav files), and 3) as a MIDI file, for those musicians who desire to work with a traditional sequencer and sampler. The spectral mix between the two loops is defined by simple coefficient controls of both magnitude and phase values. The algorithm has build upon recent work of Ravelli, Bello, and Sandler (Automatic Rhythm Modification of Drum Loops, 2007) 1 , and has relevance to music composers/producers who wish to easily and efficiently create …