Another possibility: a Quadrax + Qx. By chaining the EOR points on the Qx to each next EG and proceeding to loop things back from EOR on the 4th EG to the start on EG 1, you get this constant "strum"...with voltage control by using CV over the "attack" (in this case, it's referred to as "rise") so that you can make the "strum" longer, shorter, or more/less erratic. Works nice with VCAs, too...like having a Veils on a complex VCO with numerous waveform outputs.