Well , I would have to say KRAFTWERK , TANGERINE DREAM , JEAN MICHEL JARRE , and early HUMAN LEAGUE ( before DARE ) . KRAFTWERK used the mellotrons in RADIO ACTIVITY , TRANS EUROPE EXSPRESS , and the MAN MACHINE . Those albums are filled with mellotron choir and string sounds . TANGERINE DREAM uses the mellotron almost as well as todays samplers ( even though todays samplers are far more reliable ) , they used loop mellotrons which allowed you a longer sustain . I just bought JEAN MICHEL JARRE'S album OXYGEN and that guy has it all together as well . That album is full of mellotrons , string machines and the very rare RMI HARMONIC SYNTHESIZER . There is also some early BBC recordings with the CHAMBERLIN which predates the mellotron by about 15 years or so but that stuff is hard to find .