Molten Note (SOS 204)

Sorcery • Mana cost: {X}{R}{W} • Secrets of Strixhaven • Uncommon

Molten Note deals damage to target creature equal to the amount of mana spent to cast this spell. Untap all creatures you control.
Flashback {6}{R}{W} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

It's characteristic of the Blood Age for instruments of music to also be tools of war.

Illustrated by David Álvarez.