Most hardware synths can be connected together via MIDI (musical instrument digital interface) with using the midi in, out and thru. To make sure that all of the hard synths are able to sync to a BPM, all of the synths must follow a common clock. This clock can be set via one of the clocks in the synths or by a computer running as a master to sync the BPM.
MIDI can also be used via USB port in some cases, this makes it possible to send MIDI information from the DAW over to a synth to trigger certain notes. This will come in useful for me when I am composing my live track as I will have to worry less about my performance of keyboard playing and can set up MIDI patterns prior to my recording.
Below I have made an example diagram of 2 pieces of hardware and their connectivity which I plan to use as the bases of my track:
This diagram shows the 5 pin MIDI is connected to the Moog mother, this sends it a pulse so that the sequence on the Moog will stay in sync.
Hardware Composition Portfolio 