There has always been art beholden to the wealthy and corporate – see Michelangelo and the Medicis. In Somerville’s Davis Square, a CVS provides a window space for display; in Cambridge’s Harvard Square there’s a “25/8 artspace” window owed to zoning that keeps Santander Bank from taking up too much sidewalk. (The bank lurks immediately behind the art.) No one had to force the architecture and design firm CambridgeSeven to host a gallery, though. It was established in 1999 by a partner of the firm and is open to the public during business hours in the office part of Harvard Square’s Charles Hotel. (The complex is a good spelunk; it also hosts Pronto, a gem for breakfast and lunch.) The gallery hosted photographs by Joseph Levendusky in the spring and now “40 Years of Paint and Collage,” a show by Ruth Mordecai, through Oct. 3. Visit and look for selections from the “Container Series,” which features themes and symbols Mordecai returns to over 30 years, and new works from “The Missing Letter,” inspired by Jewish mysticism and the idea of a mythical, transformative character. 

CambridgeSeven’s Paul Dietrich Gallery, on the third floor at 20 University Road inside The Charles Hotel, Harvard Square, Cambridge.