The Jukebox video in the upper left corner of the game must have had its song flagged as broken, had all players vote to skip the song, or had its song timer hit 0:00 for the Jukebox event to be queued. It is guaranteed to be taken from the queue by the turn player during the check in such a circumstance unless they are Dead or Reincarnated (in which case the event cannot be checked).
The queue is typically checked on the visible page immediately preceding this phase, at the earliest the Effects Phase page (though this could potentially be on the 1st Resurrection Phase, or, for the 2nd Jukebox Phase, after making a choice in the Choose An Item Phase). If the visible page immediately preceding the Jukebox Phase is before the Effects Phase, the queue is checked on an invisible page immediately before the first visible Jukebox Phase page.
In a Jukebox event, the turn player must choose 1 of 6 randomly selected songs, pay 1 Rupee (one time only per phase) to get a new selection of 6 random songs to choose from, or pay 4 BG Coins to search the Jukebox Library for a specific song. Other players can see what song you chose on the page after choosing.