Singing Bell Strike is a common Enchantment — Aura card from Khans of Tarkir (KTK), collector number 55. Current market price: $0.04 (foil $0.35), TCGplayer market prices via Scryfall.
Enchant creature When this Aura enters, tap enchanted creature. Enchanted creature doesn't untap during its controller's untap step. Enchanted creature has "{6}: Untap this creature."