The program consists of two works. Here is how the BSO's performance detail page describes it:
New BSO Music Director Andris Nelsons returns for his second series of 2014-15 concerts, joining forces with several longtime collaborators for music with a Scandinavian and Slavic accent. This program features acclaimed Latvian violinist Baiba Skride, a compatriot and contemporary of the conductor, as soloist in Russian composer Sofia Gubaidulina's Offertorium-a piece recorded by the BSO in 1988 and considered one of the most important 20th century concertos for the instrument. Gubaidulina's music is strongly affected by her spirituality, making use of the modern era's wealth of expressive techniques. Closing the concert is Finnish composer Jean Sibelius's Second Symphony, a work of remarkably pastoral temperament that remains one of his most beloved works.
(Some emphasis added.)
There are the usual links to program notes, audio previews, and performer bios on the performance detail page.
The Boston Globe reviewer gives considerable attention to explaining the piece itself, which is useful, and not so much to the actual performance. He finds nothing to criticize about either, and he is also satisfied with the Sibelius. The review in the Boston Musical Intelligencer has a lot of detail about Maestro Nelsons' conducting as it was the reviewer's first time seeing him conduct. Like the Globe reviewer, he admired the violinist's playing, and also briefly noted his satisfaction with the Sibelius.
The concert was not part of my subscription, so I didn't hear it on Thursday. When I started listening on the radio on Saturday, the Gubaildina concerto was already in progress, and what I heard was not really very pleasant. Maybe it wasn't supposed to be. It became calmer and easier on the ear as it approached the end. If I read the program notes, which I hope to do, perhaps I'll appreciate it more. I'll listen to the rebroadcast, but I won't spend the money and make the effort of going in to Boston to hear it in the hall. I do like the Sibelius symphony, but I've heard it a number of times, so I don't need to attend for its sake. This isn't an easy decision. I really like to give myself the chance to hear new music, and the idea of the Gubaidulina is interesting, so going tonight is an attractive idea. But I don't quite need to be there.
As always, WCRB's BSO page has links to a lot of material about this concert and others. Check it out.