Although we can generate a variety of beeps and tones with piezo buzzers, that isn't the limit to your board's musical capabilities. John at jarv.org has taken music further and described a way to convert MIDI files into code that can generate very good renditions of the original. The process requires some open-source sequencing software and python code which converts the sequence files for use in the Arduino sketch. Here's an example of the system at work:
Very well done in our opinion. Using this method you can add very credible tunes and sound effects to your projects. So to get started, check out John's blog here. And we're on twitter, so follow us for news and product updates as well.