Sabrina Carpenter surprises fans at LA show with Christina Aguilera duet

Sabrina Carpenter has had a very, very, very good year.

Her album “Short ‘n Sweet” soared to No. 1 in the United States and other countries on its release in August. Its singles “Please Please Please,” “Taste” and “Espresso” reached Nos. 1, 2 and 3 on the Billboard Hot 100.

Last month, she earned Grammy nominations for best new artist as well as album, song, and record of the year, making her one of only 15 people ever to achieve that in the same year. Her appearance at Coachella...