The first contact with other collectors of notes in chambermusic was with the compatriot Jan A. Hollanders, living in Zaandijk, The Netherlands. He has an enormous collection of chambermusic and has made lists for several combinations: one of them for pianoquartets. His list is the starting point of the one you are about to enter. In the text you will find the initials JAH indicating Jan Hollanders. My love for the notes of chambermusic dates from the first contacts we had. I owe many items and whereabouts of notes to his catalogue Lesser-Known String Chamber Music in Print, Part III Strings and Piano.
Through him I came in contact with Peter Lang, Vancouver, Canada and the International Cobbett Association (www.cobbettassociation.org). Lang has probably the largest collection of chambermusic in the world. His musiclists are impressive. He was so kind to send me the partition dedicated to the pianoquartets.
This I combined with the Hollanders-list and with my own findings. This was the nucleus of the first edition of my own list of piano quartets. You will find his name indicated as "Lang".
In 2006 I made via Lang and Hollanders by e-mail contact with Jukka Kumpulainen, Finland. He is a professional pianoplayer with his own pianoquartet, always on the lookout for new music to perform. He had also spend many, many hours in compilating a list of pianoquartets searching extensively the internet. Our both lists were making a good match for his list covers mainly the contempory music and mine the older one. Many items on this list are due to Jukka Kumpulainen. He is indicated as "Kump".
Of course I had my own go to the internet and I had contacts with publishers. Wikipedia is a main source for data concerning the composers. Many data are from the Cyclopedic Survey of Chamber Music by W.W. Cobbett, a very useful encyclopedia, as is for the British Piano Quartets William Everett's "British Piano Trios, Quartets and Quintets 1850-1950 A Checklist" (ISBN 0-89990-095-X).
And, finally, there was research in loco, that brought me on the premisses of the Bibliothèque National in Paris, the Conservatory in Vienna, and Das Europäisches Zentrum der Künste und Das Deutsche Komponistenarchiv in Hellerau (Dresden). I loved to be there. I had a stimulating coöperation with several National Information Centres for Classical Music.
Will be there a natural stop to my activities because of a giving out of further supply of pianoquartets? There are now 1.900 on this list. My estimation is that Ï'am yet not at the last one. Most composers don't have a personal website with a list of their compositions. Their works are kept mainly in the dark. This especially is the case with composers from countries with a relative low rate of digitalisation. In countries as Russia, China and Korea there must still be a large number of "hidden" pianoquartets. I'am in 2013 just starting with the pianoquintets. My estimation is, that there are more quintets than quartets. In the end of the year 2014 we shall know more. On my explorations I was struck by the fact that there seems to be thrice as many pianoquintets as pianoquartets. That combination seems by far more popular. The number of string quartets and pianotrio's is tenfold. Nevertheless, now a day there is a rather impressing number of performing pianoquartets. The last ten years the number of compositions for pianoquartet has shown a sharp rise. This combination is growing in popularity. Recently is also popular the quartet with violin, clarinet, cello and piano, but this combination is not in my scope.