Prerecorded MP3 audio files can be uploaded and played in UpStage.
Click on the yellow "audio" button to reveal the Audio Palette. Audio files assigned to the stage will appear in a list on the right, with musical notes indicating music tracks and "sfx" indicating sound effects. Use the green arrows to scroll up and down if there are more than six tracks assigned to the stage.Click on a track and its file name will appear in one of the three slots, where you can start, pause and stop individual tracks, set looping and control the volume with the slider.
You can stop all tracks at the same time using the "stop all" button.
Click on the blue "act" button to return to the avatar tool palette. (Your avatar can still speak and move when you have the audio palette open).
At the time of writing (November 2011), the list of files in the audio palette is displayed in a random order. This is not very helpful if you have a lot of audio files assigned to one stage, as you have to scroll up and down to find the file you want. We hope to have the list alphabeticalised in the next release (v2.4.1).
There is also a known bug with being unable to stop a looping track, if after you have set it playing and looping you fill up the other two tracks and then add a fourth. The fourth track will replace the first looping track, but it won't stop it. "Stop all" will also not stop it. The only solution is to reload the stage. This bug has been lodged on SourceForge and we hope to fix it soon, but in the meantime the workaround is to be careful not to select a fourth track when the first one is still looping.