The Mark I was quickly followed in 1964 by the improved Mark II. Most Mark I's were converted to Mark II spec as well so if you
come across an original Mark I (that still works) you are looking at a very rare keyboard.

Mark II Mellotron with original 'three- arse' bench circa 1964

Also having two 35 note (G - F) keyboards side by side and built - in amplification it looked very similar. As with the Mark I the Mark
II had prerecorded accompaniments and rhythms on the left hand keyboard and eighteen 'lead' sounds on the right hand keyboard
although some were re-recorded. The sounds were arranged in six banks of three sounds with selection between the three sounds in a
bank being instant. However changing banks could take up to twenty seconds as all 35 tapes had to be moved to new positions (or
'stations') before playing could continue. Some sounds of note from the Mark I / Mark II include violins (of course), flutes, brass,
massed mandolins and 'spanish guitar phrase' (as used by the Beatles on the intro to 'Bungalow Bill').

This is the model of Mellotron used on many of the famous recordings of the late sixties which comes as a surprise to most people.
Recording studios sometimes used a modified version called the FX console with the tapes from a Mark II fitted.

About 250 were made between 1964 and 1968. Superceded by the M300.