Here’s a look inside a Mellotron M400 we just restored and an explanation of how it works! The famous (or notorious) Mellotron M400, made in the 1970s, is a unique keyboard instrument in which every key plays back a recording of that note on actual magnetic tape. This Mellotron (#1344) was restored by Alison Stout at Bell Tone Synth Works in Philadelphia, PA. Read more about this and other vintage keyboard restorations on our blog.