Besides being a leading cellist, Steven Isserlis is a dedicated explorer of out-of-the-way corners of his instrument’s repertory, and here he has devised a typically unusual cello-and-piano program. First comes Max Bruch’s Kol Nidrei, based partly on the traditional Jewish melody, and also drawing on a tune by Isaac Nathan. So Isserlis ends with Nathan’s original number—conjuring a remarkable, keening high-register tone-color for this—and with another, different version of Kol Nidrei by Ernst David Wagner. These tracks bookend the three central works. Two are cello sonatas written for a competition which neither young composer won—one by the teenage Richard Strauss and another, much finer creation by the much lesser-known Luise Adolpha Le Beau. Among Dvořák’s four Romantic Pieces, the third is an outpouring of passionate emotion, with Isserlis finding a super-intense cello tone to match.