Please check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1073]EJS version of Fourier Synthesis[/url] or [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1060.msf4019;topicseen#msg4019]Re: JAVA Sine Wave Ocsillator[/url].
You can change frequence and play the sound in real time.