Why it is that Moritz Rosenthal (b. December 18, 1862; d. September 3, 1946) chose to wait until his 65th year to make recordings is unclear. Many assume that he refused to sit for the acoustic horn because it did an inadequate job of conveying his tone. While this reasoning is sound, it fits uneasily with the facts. First, Rosenthal didn't jump at the opportunity of recording electrically: His first recording session was in November, 1927 for Parlophone/Odeon - nearly three years after the introduction of electrical recording. (No records from this session have been issued.) Second, Rosenthal made a series of recordings for Edison in March and April, 1929, at a time when Edison lagged far behind most other companies in sound quality. Sonically, the results of these sessions are only incrementally superior to the best acoustic recordings.
It's equally possible that Rosenthal refused to record out of a misplaced sense of supply and demand. We know, for instance, that he performed his two Strauss transcriptions for years before publishing them, believing it was important that they be exclusively "his," able to be heard only at a Rosenthal recital. Perhaps he believed that making his work available on records would decrease demand for his live performances.
Whatever the reasons for his delay, Rosenthal made up for a good deal of lost time once he decided to enter the recording studio. His output eventually came to over four-and-a-half hours, more than any other Liszt students expect de Greef and possibly Lamond. While many regret that the heaven-storming virtuoso Rosenthal had once been didn't make it to disk, many of Rosenthal's recorded performances are unalloyed treasures. He got an astonishingly transparent sound from his piano (a Bosendorfer in the the HMV recordings and probably in others as well), and his subtlety of nuance and quicksilver sense of rhythm give his best performances an ephemeral quality; you can hear them again and again without feeling that you truly know them. His Chopin Mazurka performances are among the few that bear comparison with Friedman's - less robust but even more charming.
It's not certain whether the older Rosenthal who has come down to us is simply the younger Rosenthal with less spectacular technique. Carl Flesch, who knew Rosenthal during his later years, implied that Rosenthal's style was evolving even in the 1930s. Rosenthal's "urge for perfection ... was admirable," he wrote. "Though advanced in years, he still tried to pursue a new and more artistic course." ("The Memoirs of Carl Flesch," p. 352.)
With the release of two Biddulph disks in 1999, virtually all of Rosenthal's recordings have been reissued on CD. These include many that were never issued during his lifetime. However, the performances are strewn somewhat haphazardly over seven CDs: Biddulph LHW 039 and 040, Appian CDAPR 7002 (two CDs) and 7013 (two CDs, but Rosenthal occupies only half of the second), and Pearl GEMM CD 9339 and 9963.
The records Rosenthal made in America for Edison and RCA and in England for HMV are well documented, and are presented complete on Biddulph LHW 039 (with the possible exception of Edison 82353 L) and Appian CDAPR 7002 , respectively. The tale of Rosenthal's travails at HMV are documented in APR's book, "Dear Mr. Rosenthal ... Dear Mr. Gaisberg ..." Rosenthal's continental association with Parlophone/Decca/Odeon and Telefunken/Ultraphon is not so clearly presented anywhere. However, bit by bit, they've trickled out. Only French Parlophone 59521-EC hasn't been reissued, though there may be additional recordings that were unreleased in his lifetime. I welcome additional information or corrections.