Emanuel Ax solos in Mozart's Piano Concerto No. 14. Michael Tilson Thomas is conductor for that and Symphony No. 5 by Mahler. Go to the program detail page for the usual links.(The link to the program detail page still works.)
On WCRB's BSO page, there is a link to their podcast, "The Answered Question," which includes an interview with the conductor, Michael Tilson Thomas. As noted there, this concert will be heard on air and over the web both on Saturday, December 5, and Monday, December 14, at 8:00 p.m., Boston Time. (On December 7, the concert of November 28 — Haydn, Bartók, and Tchaikovsky — will be rerun in the BSO time slot.)
I can't find a review of the concert in the Boston Globe or the Boston Musical Intelligencer. Both seem to review Tanglewood concerts only sporadically, which is understandable, given the plethora of concerts there every week of the summer. So you can listen without having expectations set by reviews.