A metro object is a nice object that can create a frequency and allow you to trigger and re-trigger things in sequence. 

The metro object sends out a regular beat. It can be thought of as a metronome. This object can be either fixed or tempo relative.

Polyout is created by also clicking on the object and typing polyout in the space.  

At 0 the light will be on completely and when you have 100 it will be on for 1/10 of a second with 1000 being one second.

You can control many outputs this way by duplicating this patch across many windows.

Hooking this circuit up to Channels 1, 2, 3 will allow you to control 3 LEDS in MAX/MSP and Jitter. 

Random patch for Max MSP Jitter 

Random patch MAS MSP Jitter.