Is Twinning Staff legal in Standard, Modern, and Commander?

Twinning Staff is legal in: Legacy, Vintage, Commander.

Twinning Staff

Q: What type of card is Twinning Staff?

Twinning Staff is an Artifact. Its oracle text reads: "If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy. {7}, {T}: Copy target instant or sorcery spell you control. You may choose new targets for the copy."

Artifact

If you would copy a spell one or more times, instead copy it that many times plus an additional time. You may choose new targets for the additional copy.

, : Copy target instant or sorcery spell you control. You may choose new targets for the copy.