A robot Audio System

[punarhero]

Hi all,
Our team has a project to build a robot for a museum. The robot is supposed to go to each picture, autonomously, and play a pre-recorded info. Well, our problem is what to use for the audio system. What we had thought of doing is keep a count of the picture number the robot is at, and play a corresponding track on our audio system. But there are several problems:
1. If we use a tape-recorder, we can turn the tape on when the robot is at a picture, keep time of how long it takes to play each track, then turn it off. This way we can play each track with each picture. the problem is that a tape recorder is not user friendly, and someone who wants to change a small part of the tape will have to go thorough a lot of prouble.
2. We could use a CD player, but once we turn it off, it starts off at the first track.

So, we wanted something that we can connect to a relay, turn it on and off according to the picture we are at, and play a corresponding audio track. Any suggesstions?