The well-engineered Solo: Live at Unity Temple conveys the amalgam of austerity and warmth in Steve Lacy’s recent solo concerts. His nearly twenty-minute “Monk Medley” conveys a command of material that stems from over forty years of diligent investigation. His phrasing and shading of a half-dozen Monk themes, ranging from the ebullient “Thelonious” to the pensive “Pannonica,” is supple and sure. Yet, Lacy’s artfulness in interpreting the material lies in his ability to go far beyond obvious thematic variations, while maintaining a strong connection to the pieces through temperament and tone. Lacy also ruminates upon five staples of his own prodigious compositional output-“The Crust,” “Art,” “Revenue,” “Absence,” and “Deadline” -creating a wealth of subtle cross-references between his works and those of his mentor.