Barcode & QR vs Player Piano Roll
バーコードとQRコード / 自動ピアノロール
Barcode & QR comes from Symbol Systems and Player Piano Roll from Notation Systems. Both are read here as style. They are reached for with some of the same intent, which is where they get confused.
Barcode & QR
Machine-readable graphics that print information into stripes and square grids. DENSO WAVE's QR resolves orientation with finder patterns at three corners, and the pattern-to-be-read it drew from the Go board and the newspaper halftone is now everyday scenery.
Player Piano Roll
A recording medium of rolled paper on which the punched holes are the performance itself. It marks the turn from scores read by people to codes read by machines, and it is the ancestor of the punch card and the digital sequencer.
| Barcode & QR | Player Piano Roll | |
|---|---|---|
| Era | 1974 / 1994– | 1896–1930s |
| Family | Symbol Systems | Notation Systems |
| Kind | Style | Style |
| Cues | Stripes coding by width / Three corner finder patterns / Error-correction redundancy / Pattern made for machines | Rows of perforations / The scrolling roll / Machine-readable music / Performance physically recorded |
| Best used for | Linking print to a system with a code that will actually scan · Working a machine readable panel into packaging or signage as design | Exhibiting performance data as an object a machine visibly reads · Visualizing the structure of a piece on a scrolling time axis |
| Type | Module size derived from the printing condition, with a hard minimum | Hole length is duration and lateral position is pitch, never varied |
| Composition | A clear quiet zone on all four sides, away from folds and curves | Time runs with the take up, control holes pushed to both margins |
| Material | Dark code on a light ground, no gloss and no transparent stock | Paper moves with humidity, so leave reading tolerance between holes |
| Caution | Art laid over the code spends the error correction budget, and it stops scanning in a dim shop or at an angle. | Punching every fine note thins the paper bridges until they tear, and the performance breaks down partway through the roll. |