Wikipedia:Wikipedia Signpost/2021-12-28/Serendipity

In the 1960s and 1970s Austrian pianist Ingrid Haebler was arguably one of the best performers of the piano works of Mozart. After a concert at Hunter College in 1976, The New York Times wrote about her “peculiar blend of geniality and warm sentiment”. That review, by Donal Henahan, started with this line: “Ingrid Haebler is regarded by many people, including many Viennese, as the quintessential Viennese pianist.” Henahan was right. Haebler’s respectable and quiet style was less favoured in the 1980s (as too “prim and proper”), though music lovers in Japan and elsewhere kept adoring her. Haebler was asked by Denon Records to record all of Mozart's piano sonatas. Haebler still performed in the 1990s, when she was in her sixties.

Born in 1929?
In October 2008 someone started an unreferenced short but nice Wikipedia article about Ingrid Haebler. Of course Mozart, Bach and Beethoven were mentioned. The article even included a line about the cycle of recordings by Haebler later falsely attributed to Joyce Hatto and published under her name by Hatto's husband, William Barrington-Coupe. Ingrid Habler's date of birth was given as 20 June 1929.

No, born in 1926?
In 2010 another contributor came along, and changed the birth year from 1929 to 1926, with a reference to a German source. ("Ingrid Haebler zum 65. Geburtstag (20. Juni 1991)"). The Oxford Dictionary of Music (2013) also took Haebler to be born "Vienna, 1926". One of the best German newspapers, the Frankfurter Allgemeine Zeitung, congratulated Ingrid Habler on her 90th birthday on 20 June 2016.

An authority control template was added to the article in 2012. This template lists several recognized authorities such as national libraries who give data such as preferred spellings of a person's name, and their birth dates. We can consult these sources now, but we can't say what they said back in 2012. In the meantime, the English language Wikipedia changed the date of birth to 1929, before changing it back to 1926 (in March 2017) and finally turning again to 1929 in August 2019, with a new reference.

Not born three months before her brother
So what is the truth? Was Haebler born in 1926 or in 1929? All of the fuss could have easily been prevented, if the Wikipedia community had listened better to an early contributor to the German language Wikipedia, who argued that 1926 was wrong and 1929 was the correct year of birth of Ingrid Haebler. In October 2008 Gerhard Kiefl argued at the talk page of the German Wiki article: "her brother Hilmar Haebler was born on 27 September 1926, from the same mother ... if that isn’t convincing, what is?" (my translation). Instead of checking this, people pointed to some wrong old sources, and consequently didn't want to change the (wrong) birth year 1926 to (the correct year) 1929.

The authority control VIAF lists Ingrid Haebler's birth year as 1929 in 12 references, and as 1926 in 3 references. Another authority control OCLC's WorldCat simply lists the birth year as 1929.

If "alternative facts" find their way to the real world, Wikipedians should be aware of the problem of circular referencing and different ways of resolving these apparent contradictions.

All’s well that ends well
Ingrid Haebler has given her life to music and Mozart, and in 2021 reached the respectable age of 92.

P.S. Shortly after this piece was published I received an e-mail from "the boy dressed like young Mozart" (now a man in his 60s). He still has vivid memories of that day back in 1966. He visited several concerts given by Ingrid Haebler later on- the last one in Concertgebouw Amsterdam, 2003. He lives in a street named after Mozart, and works in the flower bulb industry.