The Hyperinstruments project creates expanded musical instruments and uses technology to give extra power and finesse to virtuosic performers. They were designed to augment a wide range of traditional musical instruments and have been used by some of the world's foremost performers (Yo-Yo Ma, the Los Angeles Philharmonic, Peter Gabriel, and Penn & Teller). Research focuses on designing computer systems that measure and interpret human expression and feeling, exploring appropriate modalities and content of interactive art and entertainment environments, and building sophisticated interactive musical instruments for non-professional musicians, students, music lovers, and the general public. Recent projects involve the production a new version of the "classic" Hyperstring Trilogy for the Lucerne Festival, and the design of a new generation of Hyperinstruments, for Fensadense and other projects, that emphasizes measurement and interpretation of inter-player expression and communication, rather than simply the enhancement of solo performance.