Apple Logic Express 9 - Manual (Page 867)

The gray note head makes a note’s head, and associated ties, invisible. This note is
displayed with a gray note head onscreen, allowing further edits. Nothing but the stem
is visible in the printout.
Invisible note head
If you combine this feature with the Attributes > Stem > Hide command, you can
completely hide these notes in the printed score.
Symbols Attached to Notes in the Part Box
This group contains symbols that usually only refer to one note at a time. This includes
fermatas, accents, phrasing symbols, and bow markings, for example. (Trills are in a
separate group.)
To assign any of these symbols to a note
µ
Drag the symbol onto a note head. (Watch the help tag to ensure accurate placement.)
These symbols are automatically positioned when assigned to a note. They also move
with their parent notes, when transposed or otherwise graphically altered.
To insert a symbol that remains independent of any note
µ
Press the Option key during insertion.
This technique allows you to place a fermata above an automatically created rest, for
example.
867 Chapter 31 Working with Notation