There have been many Sesame Street videos over the years, usually featuring a mix of newly-produced material and segments from the series. Many video releases have also come with such bonus materials as activity booklets and song lyric posters. Many Sesame Street videos revolved around a certain theme, from such learning concepts as letters and numbers, to "best of" videos focusing on certain characters, to music-themed videos. Nearly every direct-to-video Sesame Street production began with a voice-over reading the title as it appeared on-screen.