can someone provide me the link for the “java package” i supposed to download for using the jsynth??
It’s located under http://java.sun.com/j2se/1.4.1/download.html
Take the “JRE” package.
Alternatively you could download Opera (the famous webbrowser) from http://www.opera.com, because it comes with the same java environment 
Best Regards, Thorsten.