Rosenboom, David; Polansky, Larry. “HMSL (Hierarchical Music Specification Language): A Real-Time Environment for Formal, Perceptual and Compositional Experimentation”. Proceedings Of The 1985 International Computer Music Conference, 244-250. Permalink: http://hdl.handle.net/2027/spo.bbp2372.1985.039
Polansky, Larry; Rosenboom, David; Burk, Phil. “HMSL: Overview (Version 3.1) and Notes on Intelligent Instrument Design”. Proceedings Of The 1987 International Computer Music Conference, 220-227. Permalink: http://hdl.handle.net/2027/spo.bbp2372.1987.031 PDF at https://eamusic.dartmouth.edu/~larry/published_articles/icmc_articles/hmsl_icmc_rosenboom_polansky.pdf
Polansky, Larry; Rosenboom, David; Burk, Phil. “HMSL (Hierarchical Music Specification Language): A Theoretical Overview”. Perspectives of New Music, Vol. 28, No. 2 (Summer, 1990), pp. 136-178 (43 pages). https://www.jstor.org/stable/833016
Burk, Phil; Marsanyi, Robert. “Iconic Programming for HMSL”. Proceedings Of The 1992 International Computer Music Conference, 166-169. http://hdl.handle.net/2027/spo.bbp2372.1992.044
Polansky, Larry. “Live Interactive Computer Music in HMSL, 1984-1992”. Computer Music Journal, Vol. 18, No. 2 (Summer, 1994), pp. 59-77 (19 pages). https://www.jstor.org/stable/3680444
Larry Polansky articles: https://eamusic.dartmouth.edu/~larry/published_articles/
David Rosenboom’s HMSL related pages: https://davidrosenboom.com/search?q=HMSL
Some articles that reference HMSL https://www.semanticscholar.org/paper/HMSL-(Hierarchical-Music-Specification-Language)%3A-A-Polansky-Burk/febe539db3c567c5c400101d17c91409a1d8ef82