This week's book giveaway is in the Agile and other Processes forum. We're giving away four copies of The Mikado Method and have Ola Ellnestam and Daniel Brolund on-line! See this thread for details.
For MP3, specifically, you can use JMF. There pure-Java version of it wouldn't require the apple to be signed, and there is an MP3 addon for it.
In the future, please UseAMeaningfulSubjectLine. "applet" doesn't provide any hint what the question is about in a forum that's completely dedicated to applet questions.