The soundtrack of screeching violins, violas, and cellos was an original all-strings piece by composer Bernard Herrmann titled "The Murder". Hitchcock originally intended to have no music for the sequence (and all motel scenes), but Herrmann insisted he try his composition. Afterward, Hitchcock agreed it vastly intensified the scene, and nearly doubled Herrmann's salary. The blood in the scene was Hershey's chocolate syrup, which shows up better on black-and-white film, and has more realistic density than stage blood. The sound of the knife entering flesh was created by plunging a knife into a casaba melon.