Is Melancholy legal in Standard, Modern, and Commander?

Melancholy is legal in: Modern, Legacy, Vintage, Commander, Pauper.

Melancholy

Q: What type of card is Melancholy?

Melancholy is an Enchantment — Aura. Its oracle text reads: "Enchant creature When this Aura enters, tap enchanted creature. Enchanted creature doesn't untap during its controller's untap step. At the beginning of your upkeep, sacrifice this Aura unless you pay {B}."