A modified playlist can be generated by identifying gaps in a playlist, and modifying other content in the playlist to fill the gap. The gap can represent previously unfilled time, or time created by removing part or all of an item already in the playlist. One or more items of content in the playlist can be modified by lengthening or shortening one of the content items in various ways, including changing a rate of playback of some or all of the items of content in the playlist. In some instances the gap can be filled or partially filled by inserting content from another server at the time of broadcast.