Pressure is force over area. So assuming your cube is at rest and on earth, then the force is mass x gravity and the pressure is mass x gravity / area.
A string quartet is made up of four musicians playing two violins, a viola, and a cello. These are all string instruments played either by plucking the strings or using a bow. The violins are the smallest and typically play the higher notes. The viola and cello are larger instruments and play the lower notes.
Since I first played oboe in a woodwind quintet at about age 13, I've been a fan. I love the richness of five distinct, heterogeneous voices that blend in innumerable ways, so unlike the insistent unity of the string quartet. (Only two of the quintet instruments share the same sound-producing mechanism, and even those two don't sound much alike. The oboe and bassoon are both double reeds; the clarinet is a single reed; the flute has a sound-hole; the horn isn't even a woodwind, but just wandered in from sheer curiosity, and stayed for 200 years.)