Instruments get into a document either by being instantiated from a template, or by being dragged in from the Library window.
The Library (Window > Library, L) window lists all the known instruments. Initially this is a repertoire of Apple-supplied tracks, but it is possible to add your own. The main feature of the window (see Figure 26.7) is the list of all known instruments. Selecting one fills the pane below the list with a description (which for now is the same as the description in the list).
Figure 26.7 The Library window is dominated by the scrolling list of available instruments. The selected instrument is described in the panel below. Selecting a category from the pop-up menu narrows the list down by task, and the search field at the bottom allows you to find an instrument from its name or description.
The library gathers instruments into groups; these are initially hidden, but can be seen if you select Show Group Headers from the Action () pop-up at the lower-left corner of the window. The Action menu also enables you to create groups of your own. The pop-up at the top of the window narrows the list down by group, and the search field at the bottom allows you to narrow the list by searching for text in the names and descriptions.