As played by

As played by is an MEI customization. It defines how an MEI document carries, beside the score, a record of one or more performances of it: which written note a sounded event realised, when it was struck, how long and how loud. The record lives in <performance>, and nothing outside it is constrained.

Example

The upbeat and first bar of Schumann's Träumerei, read from the Welte-Mignon roll 225. Hovering a <when> lights up the note it speaks about.