Master for chord progression explained?

Can anyone recommend a good video showing how to take advantage of the master to make chord progressions? Thanks

Go to the master track and press keys. This also can be recorded like any other track.

I use it to make a pattern longer. For example if I have a drum fill programmed with step components and I want to make sure the pattern plays 8 times I will make the master track 8 bars long.

@kingof9x said:
I use it to make a pattern longer. For example if I have a drum fill programmed with step components and I want to make sure the pattern plays 8 times I will make the master track 8 bars long.