When I went to school we were taught there are four basic tastes: sweet, salty, sour and bitter. First described in scientific literature in 1907, umami is now considered the fifth basic taste. I don't know if the public school curriculum has caught up with science. You'll have to ask an elementary school student.
Umami, or "savory," has long been recognized in eastern cultures. The appropriately named German chemist Karl Heinrich Leopold Ritthausen discovered the food chemical responsible for this flavor in 1866, but it took a Japanese researcher, Kikunae Ikeda, to perfect its mass production. Since that fateful event monosodium glutemate has made Chinese food taste better.
You don't have to go to Chinatown to get your MSG fix. Between JFK/UMASS and Field's Corner there are a number of Asian grocers located along Dot Ave. This is Dorchester's famed Umami Mile. Large and small concerns are located every three or four blocks. They do a healthy business.
Some people will always go to Chinatown because it is picturesque and more compact. They are cheating themselves out of Dorchester's umami experience. After all, on Dot Ave you can pick up your bok choy, MSG, hoisin and rock crabs for the week at the Truong Thinh Supermarket and then walk up to the Harp and Bard for a Guiness and corned beef platter. You can't do that in Chinatown.