The short answer
Usually, after a check. Might hold something you care about. Look inside before removing it.
What is it?
Apple’s instruments, sampler patches, loops and Drummer content for Logic Pro (and MainStage), stored in /Library/Application Support/Logic. A full installation is large, typically tens of GB.
Instruments, loops and samples (up to 70 GB). Can be moved to an external drive or reduced from Logic; downloadable again.
What happens if you delete it?
Removed packs can be downloaded again from Logic Pro at any time; projects that use them report missing content until you do.
How to remove it properly
In Logic Pro, choose Logic Pro › Sound Library › Open Sound Library Manager to select and remove packs, or Relocate Sound Library to move the content to an external drive (not a Time Machine backup volume). Avoid deleting the folder in Finder: it needs an administrator password and Logic will not know the content is gone.
From the app itself: Logic Pro > Sound Library > Relocate Sound Library, or Open Sound Library Manager to remove packs.
Before you delete it
Content here is shared with MainStage and partly with GarageBand, so removing packs affects all three.
How MoreRoom helps
MoreRoom recognises this item and labels it “Review first”: it shows what’s inside, its size and last use, so you can decide. Nothing is removed without your say, and everything goes to the Trash first, with Undo.
Frequently asked questions
Can I delete the Logic Pro Sound Library on Mac?
Usually, after a check. Might hold something you care about. Look inside before removing it. Removed packs can be downloaded again from Logic Pro at any time; projects that use them report missing content until you do.
Will Logic Pro sound library come back after I delete it?
Yes. Removed packs can be downloaded again from Logic Pro at any time; projects that use them report missing content until you do.
How do I remove Logic Pro sound library properly?
In Logic Pro, choose Logic Pro › Sound Library › Open Sound Library Manager to select and remove packs, or Relocate Sound Library to move the content to an external drive (not a Time Machine backup volume). Avoid deleting the folder in Finder: it needs an administrator password and Logic will not know the content is gone.