Synthesizers with MIDI thru output

MIDI thru

— an output that duplicates the MIDI signals received at the synthesizer's MIDI input. In other words, with such a connector, the instrument is able to pass MIDI signals through itself without change.

For more details on MIDI input, see the relevant paragraph (about MIDI signals — see the same page). Here we note that the MIDI thru output can come in handy in some specific situations — for example, when building a system of three synthesizers, two controlled instruments can be connected in series: the first one — to the MIDI output of the control synthesizer, and the second — to the MIDI thru output on the first one.