I want to put music and sounds into the game I'm working on... Since the most common music-file is .mp3 and I don't know how to change it to another type, I'm worried that I won't be able to find the sounds I want - or any sounds at all - if mp3s won't work.

What do I have to do to implement mp3s into a jFrame? Is it possible at all, or do I have to look for another type of file?

Thank you... since I don't know what an API is, I could only search for "Java jFrame mp3", which gave me no results.

Sometimes it's only the search string, but it helps to list what you've already done so people are not repeating suggestions that have already been tried.

Check JMF

That is the first link under the google search provided. ;-)

If you dont know what an API is or how to convert audio formats, maybe its a hint that your future doesnt lie in games development....