There is an AA for the 9th song. It comes from the GoD expansion and I think its 3 points and has the requirement of lvl 55.
The second target slot is the HoTT (Health of Target's Target). A few expansions back ( I forget which one) you were given "Leadership Abilities". Basically, if you are group leader, you can take a % of your experience ( like AA's) and put it to thing to enhance group play. One is the the HoTT, another being able to find any NPC in your group or inspecting another group members buffs or a spellist (tells you what someone is casting) for example. You can do gropu leader points and raid leader points, if I am not mistaken.
Now the HoTT is exactly what it says it is. Lets say you are in a group, and you target playerxxxx. If Playerxxxx is targetting mob zzzzzz, you will see that playerxxxx is targetting mob zzzzzz. Conversely, if you target mob zzzzz, you can find out who it is targetting. This works well for healers and such in a raid.
Clear as mud? lol