Practicing my cello forces me to concentrate (along with a host of other life skills, the least maybe being that I sometimes get better at the playing). My teachers for Bach Suite for Cello Solo No.2 in D Minor.–Harmon Steiner*, Yoyo Ma**, and Maurice Gendron***
Mischa Maisky: https://youtu.be/aTAASV_Rjl0
*The Maestro, my actual, in-person, teacher: his notes for how to practice a few measures are above and if I do what he gently suggests and spells out and demonstrates? It works.
** no explanation needed
***cellist on the first recording