  This paper presents a new method of encoding performance data in MEI using
the recently added \texttt{<extData>} element. Performance data was extracted
using the Automatic Music Performance Analysis and Comparison Toolkit (AMPACT)
and encoded as a JSON object within an \texttt{<extData>} element linked to a
specific musical note. A set of pop music vocals has was encoded to demonstrate
both the range of descriptors that can be encoded in <extData> and how AMPACT
can be used for extracting performance data in the absence of a fully specified
musical score.
