Jolson (also known as Al Jolson) is a period 15 oscillator consisting of two blocks hassled by two pentadecathlons. It was found by Robert Wainwright in November 1984 and named by Bill Gosper. A period 9 version that uses two snackers instead of pentadecathlons is also possible (see below). It is not possible to create a period 45 version by using one snacker and one pentadecathlon, however, as the sparks end up destroying one of the middle blocks.
One of the phases of Jolson, which led to its name