Mellotronists

When the Mellotron/Chamberlin was created... why only 35 notes??? 

from mellotron.com:
"Chamberlin Model 300/350 (two separate cabinets) and the organ style 
cabinet Model 600/660 Music Master. These machines used 3/8ths in. 
tape and had thirty five keys, G to F. Harry felt that this range was 
enough to cover the useable range of most instruments and still left 
room in the cabinet for another 35 note keyboard..."  

Harry started producing model 300/350 in 1960.

Clay