Season four premiered on January 18, 2005; this was the first season of the series to be aired in high definition, although the finale of season three was also aired in high definition. The number of those attending the auditions by now had increased to over 100,000 from the 10,000 of the first season. The age limit was raised to 28 in this season, and among those who benefited from this new rule were Constantine Maroulis and Bo Bice, the two rockers of the show.

What year did season four of American Idol first air?