In Paris in 1901 a large Van Gogh retrospective was held at the Bernheim-Jeune Gallery, which excited André Derain and Maurice de Vlaminck, and contributed to the emergence of Fauvism. Important group exhibitions took place with the Sonderbund artists in Cologne in 1912, the Armory Show, New York in 1913, and Berlin in 1914. Henk Bremmer was instrumental in teaching and talking about Van Gogh, and introduced Helene Kröller-Müller to Van Gogh's art; she became an avid collector of his work. The early figures in German Expressionism such as Emil Nolde acknowledged a debt to Van Gogh's work. Bremmer assisted Jacob Baart de la Faille, whose catalogue raisonné L'Oeuvre de Vincent van Gogh appeared in 1928.[note 15]
The self-portraits reflect an unusually high degree of self-scrutiny. Often they were intended to mark important periods in his life, for example the mid-1887 Paris series were painted at the point where he became aware of Claude Monet, Paul Cezanne and Signac. In Self-Portrait with Grey Felt Hat, heavy strains of paint spread outwards across the canvas. It is one of his most renowned self-portraits of that period, "with its highly organized rhythmic brushstrokes, and the novel halo derived from the Neo-impressionist repertoire was what Van Gogh himself called a 'purposeful' canvas".
Theo kept all of Vincent's letters to him; Vincent kept few of the letters he received. After both had died, Theo's widow Johanna arranged for the publication of some of their letters. A few appeared in 1906 and 1913; the majority were published in 1914. Vincent's letters are eloquent and expressive and have been described as having a "diary-like intimacy", and read in parts like autobiography. The translator Arnold Pomerans wrote that their publication adds a "fresh dimension to the understanding of Van Gogh's artistic achievement, an understanding granted us by virtually no other painter".
As an a cappella enthusiast, he has sung in a group called "Dick Van Dyke and The Vantastix" since September 2000. The quartet has performed several times in Los Angeles as well as on Larry King Live, The First Annual TV Land Awards, and sang the national anthem at three Los Angeles Lakers games including a nationally televised NBA Finals performance on NBC. Van Dyke was made an honorary member of the Barbershop Harmony Society in 1999.
Van Dyke made headlines again in April 2013, this time for an incident of a much different kind—one posing a threat to the actor's life, not celebrating it the way the prestigious event had just weeks earlier. The legendary performer announced that he was suffering from an "undiagnosed neurological disorder," posting on his Twitter page: "My head bangs every time I lay down. I've had every test come back that I'm perfectly healthy. Anybody got any ideas?" The famed TV personality was reportedly advised by his doctor to avoid plane travel and rest until further tests could be conducted to pinpoint the direct cause of his head pain.