THE HOUSE WITH A CLOCK IN ITS WALLS (2018) 7 p.m. on Showtime. A celebrated 1973 book by John Bellairs is given the Hollywood treatment here, in a family movie adaptation that stars the actor Owen Vaccaro as a boy who goes to live with his warlock uncle. That uncle, played here by Jack Black, lives in an old house that contains a magic clock hidden in its … well, you’ll just have to watch the movie to find out! Cate Blanchett co-stars as the uncle’s witch neighbor; Eli Roth, better known for gory movies like “Hostel,” directs. The result “doesn’t have the sophistication of an adaptation like ‘Hugo,’” Ben Kenigsberg wrote in his review for The Times. “But no film in which Cate Blanchett head-butts a vivified jack-o’-lantern could be entirely without merit.” To see Black look considerably scruffier (and to see him butcher the word “factotum”), see SCHOOL OF ROCK (2003), airing on Showtime before this movie, at 5 p.m.

GREAT PERFORMANCES: NOW HEAR THIS 9 p.m. on PBS (check local listings). The composer Domenico Scarlatti is the subject of this week’s episode of this classical music mini-series, which is hosted by the violinist and conductor Scott Yoo. The episode looks at how Scarlatti created a style of his own, and successfully straddled the Baroque and Classical periods.