渦状銀河のシンフォニエッタ (Uzujō Ginga no Symphonietta, meaning "Spiral Galaxy Symphonietta") is an original composition written for maimai DX by Mao Yamamoto (山本真央樹), a professional fusion drummer from Saitama Prefecture. Before contributing to maimai, Yamamoto made his rhythm-game debut in Konami's SOUND VOLTEX II under the alias winddrums, and later appeared under his real name in GITADORA Tri-Boost with the original track "MIND ERUPTION." His maimai debut sits at a brisk BPM of 238 and pairs driving, virtuosic drum work with a bright orchestral arrangement, fitting for a symphonietta, a short or light symphonic piece. The song arrived on August 7, 2020 as part of the maimai でらっくす PLUS update, initially locked behind the Heaven Area 2 (天界ちほー2) unlock system before a general release. The DX charts span Basic through Master, with the DX MASTER chart designed by ぴちネコ carrying a difficulty constant of 14.6. Notable for its 1,214 total notes, the DX MASTER chart features 238 Touch notes, a count that matches the song's BPM, alongside 801 Tap notes, making it one of the more demanding charts in its tier. The jacket art and in-game video were handled by illustrator and motion designer カフウ (Kafu). A separate set of Standard (ST) charts was added later on February 16, 2024 during the BUDDiES version, initially available as a 300 SP reward in Friend Battle Season 15 before a general unlock in Season 18. The Standard MASTER chart, designed by はっぴー at difficulty 14 (14.3), offers a contrasting note distribution with 159 Slide notes and no Touch notes, reflecting the differing design philosophies between DX and Standard chart families.