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“Gradus ad Parnassum” has for centuries been a name for artistic instruction guides and studies, as well as a seminal counterpoint treatise by Johann Joseph Fux, whose resplendent Chaconne is Rondeau’s penultimate track.

The album’s form is a chronological arch, bookended by Palestrina ricercars from the Renaissance and receding back in time after advancing to a 20th-century midpoint: a ruminative, persuasively fluid “Doctor Gradus ad Parnassum,” Debussy’s nod to the “Gradus” exercise tradition.

He plays a pair of pieces from Muzio Clementi’s “Gradus” collection, and flanks the Debussy with little-played, moodily lyrical Beethoven preludes.

A survey by Ukrainian market research firm Gradus found that 65% of businesses believed active fighting would be over by the end of 2023 at the latest.

Jaimie Gradus, an associate professor specializing in this subject at the Boston University School of Public Health, previously examined patterns of society-wide psychopathology in her work.