If you listen to the weekly broadcast of Sunday Baroque, you know that today is the first of our two-part Bach Birthday Bash. So today’s Beautiful Music features music by Johann Sebastian Bach, too. Violinist Hilary Hahn plays the ADAGIO movement from Bach’s Sonata #1 for solo violin. This performance was her encore of a recent orchestra concert. Since her 1997 debut album — HILARY HAHN PLAYS BACH — she has returned over and over the the composer’s genius. She was still a teenager then. Now 43, Hilary Hahn continues to reveal her maturing and captivating depth and sensitivity as a musician.