An early form of sample playback synthesizer, commonly used in the 1960s and ‘70s. The Mellotron produced sounds by means of strips of analog magnetic tape containing pre-recorded instrument sounds. Each strip of tape contained a sample which was tied to a particular key. Depending on the model, various means were available to change to different banks of sounds. Tape sets were offered containing individual instrument sounds, single notes or chords sounded by ensembles of various sorts, and rhythm and melody patterns. The Mellotron was particularly noted for its string and flute sounds, and was prominent in 1970s progressive rock. However, it was notorious for mechanical complexity and frequent need of maintenance.