Reply To: Aura of Shabbos

Interesting: One who comes to shul so late that the shul is preparing to daven Musaf should not begin with Musaf. He should start with Shacharit, despite the fact that this means he will miss reciting Musaf with the community.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:68)

I saw somewhere an opinion that says the opposite. Help, anyone?