Expanding the Power of Csound with Integrated HTML and JavaScript

This paper presents recent developments integrating Csound [1] with HTML [2] and JavaScript [3, 4]. For those new to Csound, it is a “MUSIC N” style, user- programmable software sound synthesizer, one of the first yet still being extended, written mostly in the C language. No synthesizer is more powerful. Csound can now run in an interactive Web page, using all the capabilities of current Web browsers: custom widgets, 2- and 3-dimensional animated and interactive graphics canvases, video, data storage, WebSockets, Web Audio, mathematics typesetting, etc. See the whole list at HTML5 TEST [5]. Above all, the JavaScript programming language can be used to control Csound, extend its capabilities, generate scores, and more. JavaScript is the “glue” that binds together the components and capabilities of HTML5. JavaScript is a full-featured, dynamically typed language that supports functional programming and prototype-based object- oriented programming. In most browsers, the JavaScript virtual machine includes a just- in-time compiler that runs about 4 times slower than compiled C, very fast for a dynamic language. JavaScript has limitations. It is single-threaded, and in standard browsers, is not permitted to access the local file system outside the browser's sandbox. But most musical applications can use an embedded browser, which bypasses the sandbox and accesses the local file system.