Article databases used for finding scholarly criticism also often contain reviews of performances. Below are some of the key databases with review content. Some of them also allow you to pre-limit to reviews as a publication type.
Also make sure to search Newspaper databases for additional reviews.
Full text of current issues (from about 1990) of scholarly journals published by university presses, chiefly in the arts, humanities and social sciences. Browsable by discipline and full-text searchable across all disciplines. UCLA has access to Muse e-books published from 2017-present, plus a selected number of other e-book titles.