Dancing Mad Quest help

I cannot physically do this. There is no way. The song is too fucking short, I don't have enough DPS to get through the three tower enemies and when I get to the boss, it is literally last note. I'm using Terra, Spiritus, Sarah(to get through the godawful petrifications), and Yuna

Terra: Dualcast, Ultima

Spiritus: Tolerant Wisdom, Mystic Aura, Ultima

Sarah: Age-Old Hymn, Swiftness, Spirit's Hymn

Yuna: Mana Cede, Swiftness, Grand Summon

Bahamut Summonstone with two Magic Ability 15%s on it

my Terra has 666 magic and I somehow just can't fucking do this. I'm tearing my hair out what the hell is going on

EDIT: u/Tokenstrife helped me, never mind.

If anyone else is struggling, seriously, USE HIS TEAM, it's in the comments. It takes no star levels, and your Rosa doesn't even need to be past at least 29.