Dwelling of Duels
is a website which hosts a monthly competition for musicians to arrange or cover songs from video games. It requires that the main instrument be "played live"; in other words, you can't sequence it in a computer program using your mouse or other non-instrumental means. Most of the entries use guitars, but any live instrument is acceptable, including piano, electronic keyboard synthesizer, violin, vocals, and anything else under the sun.
The songs are posted at the month's end anonymously, and the winner is determined by popular vote on the site's forum. As long as the song meets the basic requirements, it is accepted into the competition and remains hosted afterward, regardless of quality or popularity; this means that complete beginners go toe-to-toe with experienced and even professional musicians; the most well-known contributors include Jake Kaufman (who composes music for video games such as Shantae and Contra 4), Chris Kline (who has played guitar for the Video Games Live concert tour), Dennis Mott (guitarist and vocalist for metal bands Dissolution and Putrescence), and Ailsean (known for submitting that Terra In Black song to Overclocked Re Mix
This site and its songs provide examples of: