The Beethoven fest continues at Bargemusic this weekend with performances of all of his Opus 18 string quartets, of which there are six, by members of the Semplice Players along with Bargemusic’s Artistic Director, Mark Peskanov, on violin. The first concert, featuring quartets 3, 6, and 4, will be on Friday evening, December 20 at 7:00. Quartets 1 and 5 will be performed on Saturday evening, December 21 at 6:00, and quartets 2 and 5 that same evening at 8:00. Quartets 1 an 2 will be performed Sunday afternoon, December…