RTGraham:

Without knowing whether they're running some combination of publicly available products, it's difficult to conjecture as to how much the typical MIDI timing issues might affect the performance.

Yamaha has completely sidestepped all of the typical MIDI timing issues.

The Disklavier uses a special 'extended' form of MIDI that Yamaha developed ("XP MIDI"), but can also use regular MIDI.
The Disklavier also contains a dedicated computer running some kind of realtime OS that's connected directly to the sensors and actuators.

There are no MIDI DIN cables between the Disklavier computer and the sensors/actuators -- and certainly no USB or Firewire driver stack, and no Windows (or Mac) OS.

See http://zenph.com/midi.html for a brief comparison of XP MIDI with regular MIDI.
"Microsecond timing". "1024 levels of Note On, Note Off and 'Touch'. 256 levels of pedal position.
Their description is a bit off (regular MIDI doesn't have 128 levels of Note On; it has 127 velocity levels, because velocity 0 == Note OFF...)

From Yamaha's lit:

Powerful Pro MIDI Data Format Holds Expanded Performance Information
To achieve its superior standards of recording and playback performance, the Disklavier Pro Series generates extra MIDI data to accommodate precision parameters. All essential data such as hammer speed, key release speed and pedaling is recorded and reproduced within the standard MIDI format, enabling full compatibility with other MIDI devices. For recording piano performances with even further subtlety and detail, the Disklavier Pro Series also lets you select the new Yamaha XP MIDI data format.

Pro MIDI Data Format
This expanded format utilizes general-purpose controller numbers in the MIDI specification to record additional performance data including key speed and stroke depth, delivering enhanced levels of recording sensitivity and precision. This multi-mode flexibility allows interaction smoothly with existing MIDI configurations and reproduces data generated in either XP or standard mode, with automatic selection of the appropriate playback format.

How is Zenph reconstructing the reperformance data? Good question. A wild guess would be a combination of a) some really clever audio data analysis, guided by b) a digitized score of the Goldberg Variations, with c) some expert tweaking of intermediate and final results by an expert human.

- Jim

How is Zenph reconstructing the reperformance data? Good question. A wild guess would be a combination of a) some really clever audio data analysis, guided by b) a digitized score of the Goldberg Variations, with c) some expert tweaking of intermediate and final results by an expert human.

For more information: Piano Resurrection.

ORIGINAL: b rock

How is Zenph reconstructing the reperformance data? Good question. A wild guess would be a combination of a) some really clever audio data analysis, guided by b) a digitized score of the Goldberg Variations, with c) some expert tweaking of intermediate and final results by an expert human.

For more information: Piano Resurrection.

Wow - and there you have it. Thanks, b rock, for posting that. And thanks, Jim, for pointing out the XP MIDI implementation that Yamaha is using.

It still leaves the question of, "to what extent is the artistry merely the sum of its parts (i.e. high-resolution hammer velocities, release velocities, pedal positions, timing, etc.), and to what extent is there something intangible that exists only in the actual human performance, at that moment, coming from that individual?"

I'm curious now to listen to these recordings - the original Gould and the reperformance.

ORIGINAL: Marah Mag

ORIGINAL: RTGraham

Hey - what happens when you reach 1000 posts here?

I'm not sure. When I hit 999, I created a new name and started again at 0.

I'm dying to ask why, but I sense that my leg might be getting pulled here.

I'm also wondering where you got the cool avatar - noticed it on your old profile as well.

ORIGINAL: Marah Mag

ORIGINAL: RTGraham

Hey - what happens when you reach 1000 posts here?

I'm not sure. When I hit 999, I created a new name and started again at 0.

Just keep your avatar when you switch, that way we can go "Oh yeah...that's the watercolor gal"...

(that is a watercolor, right? Obviously I'm no art expert...)

ORIGINAL: RTGraham

I'm dying to ask why, but I sense that my leg might be getting pulled here.

I wouldn't pull your leg. Bascially, I wanted a different name. And the post count didn't make any difference to me. It was fun starting over.

I carefully waited until I made post 999, or maybe I waited until 1000. But the next day I saw that it was only at 996. I'm not sure how that would have happened.

ORIGINAL: RTGraham

I'm also wondering where you got the cool avatar - noticed it on your old profile as well.

It's a photoshopped photograph. I probably used a watercolor filter, or something like that.

ORIGINAL: Marah Mag

ORIGINAL: RTGraham

I'm dying to ask why, but I sense that my leg might be getting pulled here.

I wouldn't pull your leg. Bascially, I wanted a different name. And the post count didn't make any difference to me. It was fun starting over.

I carefully waited until I made post 999, or maybe I waited until 1000. But the next day I saw that it was only at 996. I'm not sure how that would have happened.

Fair enough.

ORIGINAL: Marah Mag

ORIGINAL: RTGraham

I'm also wondering where you got the cool avatar - noticed it on your old profile as well.

It's a photoshopped photograph. I probably used a watercolor filter, or something like that.

Cool.

Glad to see this thread still "charting".

ORIGINAL: Nick P

Glad to see this thread still "charting".

Heh.

One day this thread will pop up in somebody's search, and they'll read through it and ask,

"MIDI Jitter? What's that? Oh wait - I think I've heard of that - that's one of those problems people had to deal with in the first decade of the 21st century. Glad my MIDI data is word-clock-locked and sample-accurate now; I don't know what I'd do if I didn't have 384kHz MIDI resolution."

From what I gather, it's the way MIDI is processed up and down the pipe by the OS which needs reworking. MIDI events probably sit in the queue like every other process waiting to get worked over by the CPU. I think that's where the problem lies. And, MIDI is a serial interface - one note at a time - even when you play chords and such. That's always been an issue. There needs to be a MIDI 2, but I don't think there would be enough interest now.