This 90-second plug for “Star Wars: The Force Awakens” on Jimmy Fallon’s Tonight Show is as ingenious as it is entertaining. Featuring Fallon, house-band The Roots, and the Star Wars cast, the video shows the performers singing as an a cappella choir. Arranged in a grid a la Hollywood Squares or the Brady Bunch, each performer is shot against a plain background while giving their own solo rendition of the film’s most familiar tunes. By shooting at different times and places to accommodate the performers’ schedules, the producers were able to make Harrison Ford, Carrie Fisher, Daisy Ridley, John Boyega, Oscar Isaac, Adam Driver, Lupita Nyong’o, Gwendoline Christie, BB8, storm troopers, 3CPO, and R2D2, part of the all-star chorus. The juxtaposition of colored squares and overlapping of a capella voices turned the video into a spontaneous jam session, with performers playing off each other even though they were in different parts of the galaxy.