TiamaT:F minor is a high-speed instrumental track by Team Grimoire, the Japanese doujin music circle known for their aggressive orchestral-electronic sound. The song debuted in CHUNITHM AIR PLUS (July 2017) as that version's final boss, the first CHUNITHM chart ever assigned Lv.14, before crossing over to maimai FiNALE as part of the fifth Tenkaichi Otogesai (天下一音ゲ祭), an inter-arcade rhythm-game tournament spanning Sega titles. At 215 BPM, the piece layers punishing synth leads, symphonic strings, and distorted basslines into a dramatic, tension-heavy structure that mirrors its role as a climactic encounter. The title itself is a palindrome-like construction: "TiamaT" reverses the name of Tiamat, the primordial chaos goddess from Mesopotamian myth, while "F minor" denotes the composition's key. The maimai edition arrived on December 13, 2018, initially restricted to JAIA member arcades before rolling out to all regions, including international cabinets, in April 2019. The maimai version runs about 2:13, a slightly shortened edit of the CHUNITHM original (2:29) that trims the ending. A full-length arrangement titled "TiamaT:F minor -Zeit Ende-" later appeared on Team Grimoire's album UMBRA MORTIS. The music video was produced by danciao. In maimai, the MASTER chart (Lv. 14+, constant 14.6) was co-designed by 小鳥遊さん and LabiLabi, originally credited under the joint pseudonym "合作だよ" (literally "it's a collaboration"), and stands as one of the game's more demanding challenges from the FiNALE era, testing players with 1,122 notes at relentless speed. The Expert chart was designed by Jack.