Generally, a baseball game played at night. In Major League Baseball terms, a night game usually has an official starting time (first pitch) of 7:05 or 7:35 P.M. local time, which is actually before sunset in many ballpark locales for several months of the baseball season. A different start time is usually the result of a national television broadcast; for example, nationally televised night games on the West Coast often start at 5:05 P.M. so that the broadcast can start at 8:00 Eastern Time. Regardless of whether it technically starts during the day or at night, before or after sunset, at some point during a night game, encroaching darkness will cause giant floodlights encircling the stadium to be turned on to illuminate the field.
The concept of playing baseball games after dark was pioneered by Cincinnati Reds general manager Larry McPhail with the support of team owner Powel Crosley. McPhail convinced baseball commissioner Kenesaw Mountain Landis and the other National League team owners to allow the Reds to play seven night games during the 1935 season, then had light towers constructed at Crosley Field.
The first night game was played on May 24, 1935, and ended with the Reds defeating the Philadelphia Phillies 2-1. More importantly for the Reds, attendance increased for night games, at first for the novelty factor, but then because more people could make it to the games that were being played after work.
Lights had been added to most major league stadiums by the 1950s, but it wasn't until 1988 that every stadium had artificial illumination, when lights were added at Wrigley Field. The first night game to begin there was on August 8, between the Cubs and the Phillies, but it was rained out before it became official. The next night, in what became the first official night game at Wrigley, the Cubs beat the New York Mets 6-4.
Beginning in the 1950s, another advantage to night games was discovered: they allowed baseball games to be broadcast on television in prime time, thus getting higher ratings than day games. Despite the baby boomers' intense nostalgia over sneaking transistor radios into elementary school to listen to World Series games on the radio during the 1950s, TV network money won out over tradition, and the All-Star Game and all World Series games were night games by the 1970s, with all League Championship Series games being played at night by the mid-1980s. (After the Cubs lost in the League Championship Series in 1984, Major League Baseball decreed that, until lights were installed at Wrigley Field, any future Cubs World Series home games would be played at night at Busch Stadium in St. Louis. The idea that there would be Cubs World Series home games in the future has turned out to be overly optimistic.)
Meanwhile, "Night Game" is a very sad Paul Simon song. It's ambiguous whether the pitcher in the song has died literally or metaphorically, in the sense that would cause a fan to say something like, "Oh, man, he's dying out there." Also note that since it's the bottom of the eighth inning, it's presumably the visiting team's pitcher that dies on the mound.
Words and music by Paul Simon
Paul Simon, Still Crazy After All These Years
There were two men down
And the score was tied
In the bottom of the eighth
When the pitcher died
And they laid his spikes
On the pitcher's mound
And his uniform was torn
And his number was left on the ground
Then the night turned cold
Colder than the moon
The stars were white as bones
The stadium was old
Older than the screams
Older than the teams
There were three men down
And the season lost
And the tarpaulin was rolled
Upon the winter frost