Here's an old but wonderful link. Luke writes: "Hello! Look at this! It's cool! I just found this awesome web page full of virtual drum machines, thought you'd like to check it out." Alongside all the funky preset drum machines, Joseph Rivers' fantastic Keyboard Museum site is full of wonderful things. On that same page is a virtual Bee Gees Rhythm Machine, and here is a fantastic Flash explanation of how a vocoder works, complete with demos of different vocoders. Joseph, we salute you! (Thanks also to Viv and Ian and all the other people who've sent this in over the years...)