GrayAMP's player interface is divided into two areas. On top, is the Player controls, and on the bottom is the Playlist.
(Note: The pictures on this page are all gray scale to save on disk space. )
The Player
The first two items in the window are status indicators, Song and Time.
 
The current song is just that, it displays the file name (who needs ID3v2 tags).
Time has 3 modes, Remaining/Elapsed/Total, which you can cycle through by clicking on it. This is only enabled however when using QuickTime 4 as the engine. (See Preferences).
Next, we have the actual Player controls.
 
These buttons control the playback of the song(s).
Finally, the Playlist controls.
 
The disclosure triangle show/hides the Playlist, and the Shuffle and Loop buttons are sticky (they stay down, as they should). A note on Shuffle, when enabled the "Prev" button will be disabled. This is something you will have to learn to cope with.
The Playlist
 
The Sort buttons atop the Playlist sort the Playlist when clicked. However, they are not "sticky" like in Finder-list views.
 
Items can be added to the Playlist by Drag & Drop. They can be rearranged by drag & drop also. Hitting the Delete key removes items. The icons are not controls, merely status indicators as to weather a song was played or not.
 
For those of you not accustom with OS 8.5, those little stripes are the Grow button for the Playlist.