If you've ever dreamed of composing cheesy scene transition scores that might accompany animations or Gameboy games, you need to check this this thing out.
Local musician and software developer Steve Goldberg has built a Roland Juno-106 synthesizer from the 80s that can be played right on your browser.
Technical.ly Philly reports that Goldberg built the synth in Javascript using the WebAUDIO and WebMIDI APIs, along with some other tools that helped add functionality on the front end.
While using a mouse or trackpad doesn't really allow you to pull off the kinds of speedy arpeggios and Cars-style power melodies you might want to, Goldberg really created it to be played using a MIDI Keyboard. It's still a totally pleasant bleep and bloop experience in its own right, though.
Check out the creator's bands, Resistor and Steve Goldberg and the Arch Enemies.