The finals are broadcast in prime time from CBS Television City in Los Angeles, in front of a live studio audience. The finals lasted eight weeks in season one, eleven weeks in subsequent seasons until seasons ten and eleven which lasted twelve weeks except for season twelve, which lasted ten weeks, and season thirteen, which lasted for thirteen weeks. Each finalist performs songs based on a weekly theme which may be a musical genre such as Motown, disco, or big band, songs by artists such as Michael Jackson, Elvis Presley or The Beatles, or more general themes such as Billboard Number 1 hits or songs from the contestant's year of birth. Contestants usually work with a celebrity mentor related to the theme. In season ten, Jimmy Iovine was brought in as a mentor for the season. Initially the contestants sing one song each week, but this is increased to two songs from top four or five onwards, then three songs for the top two or three.