Lets say you want a note to never end. You could either make an absurdly long clip with a note that is longer then your song. Or play with the attack and release of the instrument to make it sound like a smooth loop.
Neither of these methods really achieves the task we wish to do. Luckily there is a feature in Live just for this reason.
Make the note a bit longer then the loop. And let the loop have a lead-in.
For example: The note starts 1.1.1, Make the loop start at 1.3.1 and let the loop end at 2.1.1. The note ends at 2.1.2, past the end of the loop.
Now you have an endless note.
