After the pandemic hit and musicians migrated online to share their performances, Nicholas Kitchen, the first violinist of the Borromeo String Quartet, built a little "concert shell" in his Boston-area loft he calls "MusicKitchen." It's a practice space for the group which he shares with his wife, the Borromeo's cellist Yeesun Kim. Like the shells in regular concert spaces, but on a tinier scale, the Kitchen shell (seen behind the players in this video) helps project the sound. And the sounds Kitchen wants to emphasize in this concert come by way of Beethoven, the composer born 250 years ago this week.