RPG Vault have posted the third Anarchy Online: Shadowlands Blueprint in which the team reveal some key aspects of the game such as the Music and Environments:
AO and Shadowlands use - and benefit from - our own 'Sample-based Interactive Music player' (SIM-player for short). This player was developed to give us the opportunity to make the music interactive and directed by the actions of the players. A dynamic experience in other words.
One example of the advantages of this tool is the battle music, which consists of multiple layers and transitions that are controlled by the intensity, length, player side and outcome/balance of the fight. Instead of just one repeating theme over and over, you will constantly get new variations due to this technology.
An example of this can be found in who you pick a fight with. If a superior player fights a small Leet, and the creature is killed within seconds, we don't want that full-scale action music, only a small hint of some tension. However, when a high-level team picks on one of the new Brink creatures - which really puts up a fight :) - the music will reflect a higher level of action and drama. If the creature gets the upper hand during the fight, the music will turn more frenetic and reflect the desperate situation of the players.