Toggle Storyline Mode with the G Shortcut in Final Cut Pro

What the G Key Does

In Final Cut Pro, pressing G toggles Storyline Mode. Apple describes it simply: it toggles the ability to build storylines when dragging clips in the timeline. When Storyline Mode is on, clips you drag into the area above or below the primary storyline are built into connected storylines, so they stay grouped together. When it's off, clips you drag land as individual connected clips.

It doesn't change the primary storyline, and it doesn't turn off the magnetic timeline. It only changes how connected clips behave when you drag them.

Why Storylines Help

A connected storyline is a group of connected clips that behaves like a mini primary storyline. Clips inside it stay end to end, you can add transitions between them, and you can move the whole group with one drag. That makes B-roll sequences and cutaways much easier to manage.

How to Use It

Open a project with some clips in the primary storyline.
Press G to turn Storyline Mode on.
Drag a B-roll clip from the Browser into the area above the primary storyline.
Drag a second B-roll clip right next to the first. Both become part of one connected storyline.
Press G again to turn Storyline Mode off when you want clips to land as separate connected clips.

Tips

Keep an eye on the timeline controls so you know which state you're in before you start dragging.
If you already have loose connected clips, you can still select them and press Command-G to create a storyline from them.
Storyline Mode is a toggle, so it stays on until you press G again.