Anthony Storr (1920-2001) was a gifted psychologist who wrote with great clarity about music. I use his book "Music and the Mind" as the cornerstone of a course I created at the University of Bridgeport called "Music in the Liberal Arts."
Storr also wrote a book called "Solitude; A Return to the Self" in which he distinguishes between solitude and loneliness and explores the "uses of solitude." Unlike loneliness, solitude can be nourishing and restorative.
As one observes Mstislav Rostropovich walking the grounds of the Vézelay Abbey no further proof seems necessary:
During the first minute of video he talks of playing the cello as if he were singing. "Then debilitated from his long stay in the heights," says Rostropovich of Bach's lines, "you descend once more to garner a new source of energy."
He describes the sarabande of the second suite [1:05] as "the saddest of all the sarabandes in the suites." It encapsulates a "musical vulnerability like that of a person rapt in prayer."
The second suite's sarabande is a prayer, but it is a prayer of motion; of movement. In his performance [2:41-3:12] Rostropovich brings out the fierce and unpredictable skips that tear through a work which up to this point has sounded ancient and meditative.
As he turns a corner in an ancient churchyard [2:05] the camera gradually reveals a rich background; a village below and hills stretching to the sky. "For me," he says, "this Sarabande has the white hot intensity of solitude."
He observes birds flying higher into the sky before roosting [2:57]. "They're pretty noisy, by the way." Noisy enough to delay the recording process until night falls. Then Rostropovich plays the sarabande of (and with) white-hot intensity.