Styles of Transcription
How fans online transcribe music from video games varies based on the particular YouTube user's musical abilities and their audience. One way to make music more accessible to fans who do not read music is to use forms of notation other than Western staff notation. Guitar magazines have practiced this for years, in the form of tablature, often instead of or alongside traditional notation, so fans who do not read music can play riffs from their favorite songs.
Piano roll notation has become popular on YouTube as a music educational tool; for example, to show counterpoint or texture in classical music. (YouTube user smalin has created a number of piano roll notation videos for pieces ranging from Bach fugues to Stravinsky's Rite of Spring; they use different colors to differentiate between lines and different shapes between instruments.) Fans have begun using it in order to help make their transcriptions accessible to a larger audience, including piano learners and those who cannot read music. It includes the piano roll on top while the necessary keys on a piano are played -- simulating an actual player piano as the roll rolls out in front of it.
The video above displays the theme for "Ecruteak City" from Pokémon Gold, Silver and Crystal (1999-2001, Nintendo Game Boy Color), as arranged for the piano roll program "Synthesthesia" by YouTube user TheRedSock. For comparison, here is the original Game Boy version:
"Ecruteak City" was re-arranged for the remake games Pokémon Heart Gold and Soul Silver (2009-2010, Nintendo DS). The more sophisticated arrangement for the updated game reflects the sounds of Japanese traditional instruments, to represent Ecruteak's "historical" environment, but other than adding a short introduction, it retains the same melody. This is a form of world-building: Ecruteak City is based on Kyoto, the ancient capital of Japan that is known for its many temples and other historical sites. Many of Heart Gold and Soul Silver's musical changes are designed to better reflect the cultural and geographical differences between locations in the game.
TheRedSock claims to have taken their transcription from another YouTuber's (kamotakukano) arrangement of the Gold/Silver/Crystal Ecruteak City theme, which they perform on piano here:
TheRedSock's channel contains various piano roll transcriptions of video game and anime themes, including themes from Miyazaki movies. This is a way that fans attempt to make music accessible to other fans who have different sets of musical skills.