(Some emphasis supplied) See that page also for the usual links: performer info, program notes, and audio previews.
The program, unusual as it is, fits well with Maestro Roth's experience in conducting everything from baroque to contemporary music with orchestras he has founded, so even though he hadn't planned he, he was a natural to take it over unchanged.
I was there on Thursday, and I thought the Bach worked well on modern instruments. The Stravinsky piece is beyond my powers of description — I advise reading the program notes and listening with the text available if you're not already familiar with it. And I do recommend listening. It is clearly a heartfelt piece, and it seemed well performed, as far as I could tell. The Beethoven Elegiac Song is a little gem, also worth having the text available. As for the 4th Symphony, it is my least favorite among Beethoven's symphonies: while the first movement is okay and the second is gorgeous, the last two are altogether too brusque and coarse for my taste (sort of like the scherzo in the 9th). But the performance on Thursday smoothed out the last two movements enough that they actually seemed musical to me. Of course, the fast and loud ending brought the obligatory standing ovation from most of the audience.
The Boston Globe's reviewer's description of the Beethoven 4th performance suggests what there was that let me like it better than I had expected. He was non-committal about the Stravinsky, and less than thrilled with the Bach. On the other hand, the reviewer in the Boston Musical Intelligencer was happiest with the Stravinsky, liked the Elegiac Song, and found the opening and closing pieces a mixture of good and not-so-good. BTW, the review also has some good pix.
You can listen on WCRB, Classical New England, at 8:00 p.m., Boston Time, this evening, and again on April 21 (thereafter streamed on demand). A schedule of their remaining BSO broadcasts/webstreams of this BSO season and links to other features (including an interview with the conductor) are on their BSO page. On Monday, April 14, the rebroadcast/stream is of last week's concert, which included the new concerto for piano and orchestra by Bernard Rands.