Today's performance was by Tanya Tomkins, playing Bach unaccompanied cello suites 1 and 5. She used a Baroque cello (from 1798 England), which sounded and looked slightly different than the modern version. She explained at the break between pieces that the strings were rotgut rather than steel, and there was no endpin so she needed to hold the cello between her knees.
My father is a professional cellist, and I love the sound of the instrument. The Prelude to Suite No. 1 (in G major) is probably one of the most recognized cello pieces. I have a recording of Yo-Yo Ma playing it. Tomkins did a fine job. For Suite no. 5 (in C minor), she tuned the A string down a step, which she explained as scordatura or alternate tuning; a technique very familiar to guitarists, though I hadn't heard of its use in classical music before.
Always a treat to hear some fine live music on my lunch break!