an Entity references as follows:
Concerto n °2 en si bémol majeur op. 19 / Beethoven, comp.; Daniel Barenboïm, p; the new Philharmonia orchestra; Otto Klemperer, dir. / Beethoven, comp; Daniel Barenboïm, p; the John Alldis choir; John Alldis, dir.; the new Philharmonia orchestra; Otto Klemperer, dir.