I *always* forget this easy workflow for renaming large amounts of items in a folder (on a Mac), good for more than sample libraries.
BE VERY CAREFUL! THIS RENAMES ITEMS AND YOU CANNOT UNDO IT.
2) Select "Workflow."
3) From "Library" click "Finder."
4) In the column that opens up to the right, select "Get Selected Finder Items" and drag it into the Workflow.
5) In the same column, select "Rename Selected Finder Items" drag it into your Workflow after choosing to duplicate or not.
6) I then select "Make Sequential" and click "New Name" and enter the desired name.
7) Go to your Finder/Folder and select the items to be renamed.
8) Return to Automator and click "Run."
So easy, but do be careful, you can rename more than you want to with an accidental selection.