There is no trigger for when a file is added to a directory. If the file is uploaded via a webpage, you might be able to make the webpage do it.
You can put a script in crontab to do this, on unix machines (or task schedular in windows). Google crontab for a how-to.
As for combining your commands, use the following:
mv *.mp3 *.ogg ../../Music
You can include as many different “globs” (filenames with wildcards) as you like. The last thing should be the target directory.