You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
American_Idol

Context:
David Archuleta's performance of John Lennon's "Imagine" was considered by many as one of the best of the season. Jennifer Lopez, who was brought in as a judge in season ten, called it a beautiful song-moment that she will never forget. Jason Castro's semi-final performance of "Hallelujah" also received considerable attention, and it propelled Jeff Buckley's version of the song to the top of the Billboard digital song chart. This was the first season in which contestants' recordings were released onto iTunes after their performances, and although sales information was not released so as not to prejudice the contest, leaked information indicated that contestants' songs frequently reached the top of iTunes sales charts.

Question:
Which contestant sang "Imagine" on season seven of American Idol?

David Archuleta