In Rocksmith how do I "Reach master mode on a phase"?

One of the 3 suggested goals to attempt literally states "Reach master mode on a phase". I'm not sure how to complete this task. I tried playing in song mode and improving myself in sections so they turn pink in the small song section overview, but it didn't register as completed so far.

Questions:

• Am I maybe supposed to reach 100% score on that section to complete the goal?
• Is a pink section the indication it's in master mode, or is master mode the "pro" mode where you don't see the notes anymore?
• Can it be reached in song mode or do I need to go into practice mode?

Edit: To clarify the above 3 questions after completing the goal last week: 1. Just play the section without (too many) error a few times. 2. Pink is not master mode, the notes start fading out when master mode is active. 3. I completed it in song mode.

Basically, there are a couple of things that need to be done here for this to apply. Firstly, you need to make sure that "Master Mode" is enabled, and you also need to "level up" a phrase in a song in order For "Master Mode" to apply/kick in.

From the Ubisoft Forum it seems that not only is this incredibly vague, but also potentially mildly bugged:

Go into the options menu and play settings and make sure Master Mode is enabled. If it is already enabled I would disable it, back out, then go back in and enable it.

Then play one of the songs that you have leveled up and as you nail fully leveled sections you should see Master Mode kick in.

This Reddit thread also provides a little more detail about what you should be seeing:

As far as I can tell, just getting 100% on a phrase in Learn a Song doesn't immediately throw you into Master mode. It takes a number of repetitions before the notes start to fade.

You need to play the phrase at 100% a few times (not sure how many), you will see the notes becoming fainter and fainter until they disappear, that's master level.