Conway's Game of Life is a cellular automaton (a model that attempts to replicate the behavior of living cells) developed by British mathematician John Horton Conway in 1970. It takes the form of a grid with pixels that can either be in two states, on or off, or alive and dead since this is supposed to a model replicating the behavior of biological cells. The cells start in a state (alive or dead) either chosen at random or by a user and then the state of the cells is constantly changing and determined by specific rules.The rules determining the state of a cell are as follows:
- Each cell with one or no neighbors dies, as if by solitude.
- Each cell with four or more neighbors dies, as if by overpopulation.
- Each cell with two or three neighbors survives.
- Each cell with three neighbors becomes populated. 
There are other cellular automata with other rules, but Conway's Game of Life is one of the earliest and most popular examples. It is also even possible to create three dimensional cellular automata, but most of them (including Conway's Game of Life) are two dimensional.
Some artists have taken cellular automata (either Conway's Game of Life or similar ones) and used them to create new pieces. One such example is Alexander Dupuis's piece Conway Quartet, a music piece based on cellular automata which he describes as
A Game of Life-based audiovisual synthesis system: four one-dimensional voices interactively manipulate themselves through shifting phase triggers and cellular waveshaping. 
Another piece similar to Alexander Dupuis's Conway Quartet is Carla Scaletti's piece sunSurgeAutomata. sunSurgeAutomata also uses a cellular automaton to create algorithmic music, however all of the sounds are derived from "clicks" organized by the cellular automaton. Carla Scaletti had this to say about her inspiration for the piece:
One of my goals was to create a computer-generated piece that was not based on a model of ‘instruments’ playing ‘notes’; instead, the structure arises from the self-organizing patterns that emerge when you apply the simple (local) cellular automata rules to pulses or as a signal processing algorithm. 
It is interesting how both Alexander Dupis's Conway Quartet and Carla Scaletti's sunSurgeAutomata are both so similar in concept, a piece of music derived from a cellular automata, but so different in execution. Dupis's piece uses the cellular automata for waveshaping, which is the process by which a simple audio signal (like a sine wave) is altered to create a more complex sound. In Conway Quartet, there are only four different voices playing simultaneously, and the cellular automata is determining what those four voices sound like. sunSurgeAutomata, on the other hand, actively tried to avoid such an approach. sunSurgeAutomata is a piece made from clicks derived from the cellular automata, so there are potentially much more than four voices. The two sound similar in the sense that they both lack any sort of discernible pattern or rhythm since they both aim to portray the biological-like nature of the cellular automata, but sound different because the way they capture that essence is completely different.