On Mon, Feb 16, 2015 at 12:11 PM, Jonathan E. Brickman <jeb@ponderworthy.com> wrote:

1. Is MIDI-over-USB as constrained in timing, as MIDI-over-DIN?

No.

2. I had not heard of MIDI-over-OSC. And although I had heard of MIDI-over-Ethernet I had not thought of this context. Is it possible to send MIDI events, either encapsulated in OSC or by USB or Ethernet, without that low timing resolution of the DIN setup? If I set up something like USB-MIDI-to-Ethernet, is it possible to see real advantage?

No. But almost nothing talks MIDI-over-OSC, it is just a gimmick. ipMIDI is more widely used, but as usual there are competing standards for MIDI over ethernet and ipMIDI is actually the lesser used of the two - I forget the name of the other one.

3. Is JACK MIDI constrained in the low timing resolution of original MIDI, or is it more flexible?

Not constrained. JACK MIDI has essentially instantaneous transmission between clients. When talking to external hardware, the timing is dictated by the device driver API being used.