there are many, but four immediately come to mind
keith jarrett trio w peacock and dejohnette at san fran masonic center roughly 2008 - played three encores, we sat in 10th row could hear the instruments without amplification
dianne reeves and her band at sf herbst theater in 2011 she was performing brazilian music ... lovely concert, then for the last two numbers and encore, she sang with acoustic guitarist romero lubambo without microphones... it was an awesome experience to hear the natural sound in a beautiful hall
bobby mcferrin with a full choir at herbst in 2012 - he orchestrated the voices and did his amazing thing... stunning artistry and naturalness of massed voices in amazing improvised arrangements, we visited with him afterwards with my family and a friends, he did a little sing along with the kids after, just amazing ... he is an angel walking this earth with us
chick corea and bela fleck at the sonoma state university green center in 2015 just awesome artistry and skill