Question

correct the text by inserting or removing commas. there should be a total of four commas. (note: in this skill, serial commas are not optional.)
the new york city ballets october 11, 1948 debut featured three pieces:
symphony in c, orpheus, and concerto barocco.

Explanation:

First, confirm existing commas: the date has 1 comma, the list has 2 commas (including required serial comma). We need 1 more comma. A non-restrictive appositive-style comma is needed after "1948" to separate the specific date from the noun "debut" it modifies, as the date is extra descriptive. This brings the total to 4 commas, meeting the requirement.

Answer:

The New York City Ballet's October 11, 1948, debut featured three pieces: Symphony in C, Orpheus, and Concerto Barocco.