It’s interesting how, in this information age, so much misinformation can proliferate unchecked and uncorrected. This is as true in Classical Music as it is in politics, and nowhere more than at Google’s Classical Music Recordings Group. This is, for example, the group with several members who unwittingly perpetuated the Joyce Hatto fraud. Most of the group’s members are dilettantes who fancy themselves as experts in music, and several of them are unschooled in the basics of social conduct. A few are actual musicians - some of whom remain as professional musicians and others who've gone on to other professions. I made a few posts to the group about a decade back, realized what the group was dominated by trolls, and quickly disassociated myself with them. But I occasionally view posts (“lurking is the Internet term) as there are a few members who occasionally post about upcoming recordings. A recent post concerned the piano used by Vladimir Horowitz as his 1986 Moscow recital, the recording of which was recently reissued. One poster complained about the piano’s “tinny” sound, and speculation arose as to whether Horowitz was using a piano supplied by the Moscow Conservatory, as pianos were notoriously poorly maintained in the USSR.
There is no equivalent to Politifact in Classical Music. So, in this instance, I will provide the facts - just the facts, and not my own personal opinion on the quality of Horowitz's pianos. Accurate information about Horowitz’s pianos has been publicly available for decades now. The pianist's tuner, Franz Mohr, gave a rundown about the pianos used by Horowitz in his book, My Life with the Great Pianists, which was published in the early 1990s. I expanded on Mohr’s information when I put together the Horowitz FAQ section of the pianist’s informational website, from which the information below is adapted.
The Pianos Used by Vladimir Horowitz
Early in 1934, as a wedding present, Steinway presented Vladimir and Wanda Horowitz with a Steinway Model D, Serial #CD279503 (the "C" denotes for pianos deemed worthy by Steinway for Concert use. The "D" indicates the size of piano, in this case, nine feet long). This piano was kept in Horowitz’s homes (he moved several times before purchasing a townhouse on Manhattan’s East 94th Street in 1939) and not used for concerts or recordings.
In the early 1940s, this piano was replaced with CD314503. This is the piano Horowitz kept in his New York townhouse, and used in recitals and recordings from 1974-1981 and 1985-1987. This is also the piano which has “toured” Steinway dealerships in North America and been used in a few recordings over he past 25 years – although it has been reworked so extensively it bears little resemblance to the piano that Horowitz knew.
CD186 (Steinway often dropped the first three digits with "CD" pianos) was selected by Horowitz for his return recital in 1965. (He described the tone as "more mellow [than CD314503], more like the human voice.") CD186 was used for subsequent concerts and recording sessions until it suffered catastrophic failure in late 1972 and was retired from professional use.
CD223 was kept at Horowitz’s summer home in New Milford, Connecticut. It replaced CD186 for Horowitz's last Columbia sessions in late 1972/early 1973.
CD75, built in 1911, was found by Franz Mohr, Horowitz's tuner, in Steinway's basement and restored by him. Horowitz used the piano from 1981-1983.
CD443, Horowitz's last piano, was selected by the pianist for home use, to avoid the inconvenience of hauling CD314503 from Horowitz's second floor living room when he went on tour. At first Horowitz had reservations about the piano's action (which was rather heavy) but came to love the instrument so much that, when he briefly considered concertizing in 1989, he planned to take CD443 with him. This piano was used for recording sessions made at Horowitz's home in 1988 and 1989.
Incidentally, for his first four Columbia Masterworks recordings, made between 1962-1964, Horowitz used a piano supplied by Columbia’s 30th Street Studio. However, when he returned to studio recording in 1969 (all of his 1965-1968 recordings were compiled from live appearances), he found that the piano he’d used for the earlier sessions had been tampered with by Glenn Gould, and was no longer palatable.