"Bad Apple!!" is a frequently ripped track from the Touhou Project series and a major meme on the SiIvaGunner channel. It refers to both the original Touhou 4: Lotus Land Story song and its electronic remix by Alstroemeria Records.
The song first appeared in Touhou 4: Lotus Land Story which was released in 1998. It is played during the third stage of the game. In Touhou 5: Mystic Square, it was included in the music room, and subsequently featured in the official doujin album "History of Yougakudan 1 ~ Akyu's Untouched Score vol.1." in 2006. ZUN has stated that the song was reminiscent of his older works.
Bad Apple!! feat.nomico[]
"Bad Apple!! feat.nomico" is a remix of the song, included in the album "Lovelight" and released on May 20, 2007 by the doujin circle Alstroemeria Records. It was remixed by Masayoshi Minoshima with lyrics written by Haruka and vocals provided by nomico. This remix is actually mostly original other than the prominent inclusion of the first melody in the original "Bad Apple!!". It proved to be extremely popular, especially after a shadow-art video was created for it.
The first rip of the song itself was "Bad Apple!! - Touhou 4: Lotus Land Story" which was uploaded on March 4, 2016; while the first rip to feature the song as a joke was "Dark Cave/Ice Path - Pokémon Gold & Silver" which was uploaded on April 20, 2016. Since then, it has become the most used Touhou Project song in rips by a large margin. The "Bad Apple!!" Day event in 2017 was dedicated to the song in recognition of the remix's 10th anniversary.
In melody change rips, the Alstroemeria Records version (which elevates the sixth note in the first measure by an octave and the second note in the fourth measure by five semitones) is most often used, rather than the original melody; though on occasion, rips will use the altered melody from the remix alongside the melodies from the original that weren't adapted by the remix. It is also notably paired with the Inspector Gadget theme song on occasion due to the first five notes being shared between the two melodies.