> Sorry, but it seems you don't understand MIDI at all.
>
> The Synths do not receive a clock which transmits a tempo, but they
> receive individual notes.

I don't know about many specific individual synths, but in general, MIDI can indeed send a 24PPQN clock pulse out, which can easily be converted to the DIN sync standard as it's essentially an encoded version of that anyway. It isn't technically a tempo, but you can count the pulses and increment the cursor in your synth's sequencer accordingly. This is quite separate, and in addition, to sending out the notes. Or, for that matter, CC controller/value pairs, or even sysex dumps.

See http://www.gweep.net/~prefect/eng/reference/protocol/midispec.html#Seq for more information on this.

All the best,
Zoë.