Add Files (Ctrl-F)

This allows you to add files to be corrected.  Added files appear in the File List.

Add Folder (Ctrl-D)

This allows you to add an entire folder instead of having to manually select all file in a folder.  Added folders appear in the File List.

Select All Files (Ctrl-A)

This selects every file in the File List.  This option is unavailable if the File List is empty.

Select No Files (Ctrl-N)

This unselects every file in the File List.  This option is unavailable if the File List is empty.

Invert selection (Ctrl-V)

This inverts or toggles the selection status of every file in the File List.  If a file is selected, it becomes unselected.  If a file is unselected, it becomes selected.  This option is unavailable if the File List is empty.

Clear selected file(s)

This will remove all selected files from the File List.  This option is unavailable if the File List is empty.

Clear All files

This will remove all files from the File List.  This option is unavailable if the File List is empty.

Exit

This quits MP3Gain.