Tamusic
An instrumental music circle that does piano and violin tracks. This circle's genre ranges from classical to rock and also do arrangements of other games and anime. I first heard TAM through this arrangement of Flowering Night on Youtube.
フラワリングナイト (04:47)
original title: フラワリングナイト
source: 東方花映塚 ~ Phantasmagoria of Flower View
They have a LOT of arrangements of Flowering Night specifically, with 92+ songs. They probably have the whole song memorized on their violin, granted, it is a rather repetetive melody.
My favorite TAMUSIC songs are from the Violin Rock albums, they sound straight out of an anime battle scene. Great stuff to daydream to.
亡き王女の為のセプテット
arrangement: TAM×KEIGO KANZAKI
original title: 亡き王女の為のセプテット
source: 東方紅魔郷 ~ the Embodiment of Scarlet Devil
幽雅に咲かせ、墨染の桜(東方妖々夢)
original title: 幽雅に咲かせ、墨染の桜 ~ Border of Life
source: 東方妖々夢 ~ Perfect Cherry Blossom
He has a youtube channel where he posts some Touhou and arrangements from other anime and games.