Nowadays, we can hardly see improvisation in classical music and general opinion is that improvisation is not acceptable in classical music! But before classical music became academic, all great composers and performers were great improvisers. Bach, Mozart, Weber, Beethoven, Chopin, Liszt, Schumann, Brahms, Tchaikovksy, Saint-Saëns, Mahler, Debussy, Scriabin, Bartok etc...
In this video, I show 13 improvised piano plays. Besides composers such as Saint-Saëns, Elgar and Albeniz, there are also great virtuosos such as Horowitz and Hofmann. Some improvisations are just a simple piano exercise, some a simple spontaneous prelude before starting the piece, some embellishment; I tried to combine all kinds of improvisation.
* I deleted Hofmann's recordings from this video. Although I still think that Hofmann performed spontaneously, but it is not possible to prove this, and when I evaluated the objections, I decided that it should not be included in the video. Hofmann makes it clear in his book that he hasn't worked before, and he tends to be very, very spontaneous at concerts. He recorded that waltz many times and never did anything like that. Hofmann came from the tradition of the 19th century; his teacher, Anton Rubinstein, is famous for making similar improvisations. Well improvised pianists like Horowitz, Cziffra, Rachmaninoff do not play spontaneously. Spontaneous piano playing is a different phenomenon; Pianists from the 19th century tradition such as Pachmann, Paderewski and Hofmann play each piece spontaneously in concert. That's why I judged it to be improvised, but that's a bit of a subjective opinion. I didn't want to host an imprecise recording in the video.
00:00 Vladimir Horowitz
This is Horowitz's kind of exercise improv rehearsal before the concert (Carnegie Hall, April 14, 1965).
02:37 Glenn Gould
This is an excerpt from "Glenn Gould: On the Record", a 1959 documentary. Taken during recordings of Bach's Italian Concerto, at Columbia 30th Street Sutudios, New York Jun.23～26, 1959. Here Gould is improvising freely, possibly on the theme of Debussy Clair de Lune.
3:33 Samson François
The date is 1968. I don't know the original Footage source. I got the video clip from "Clément Le Masson" KZfaq channel.
4:29 Moriz Rosenthal
Rosenthal improvises before entering his own cadenza. This is from 1929 Rosenthal's broadcast live Hungarian Rhapsody No. 2 performance, should not be confused with the well-known studio recording.
5:12 Camille Saint-Saëns
1904, Cadenza for "Africa" (Fantasie for piano and orchestra, Op 89). He plays the themes and makes improvisational additions. But thankfully @Kris9kris warned me, there are some improvised parts here of course, but I need to point out that many themes belong to the original work. Piano experts like Jonathan Summers say it's improvised and it is also mentioned in some books, for example "The Cambridge Companion to the Piano". But don't take it all as improvised, more like improvised bridges over themes.
7:57 Enrique Granados
It is an improvisation on themes from Granados's "El Pelele", 1912.
10:58 Isaac Albéniz
Albeniz recorded three improvised piano performances in 1903. This is the second of those three recordings.
13:00 Edward Elgar
Elgar recorded five improvised piano performances in 1929. This is improvisation number four.
17:36 Charles Ives
1937, a piano improvisation by the composer Ives.
18:24 György Cziffra
Rec. 1960, in Paris.
20:00 Jorge Bolet
An improvisation from Bolet's private performance for his friends, 19 April 1987. I got the audio from "Helen and Herman in Lawrence" KZfaq channel.
22:28 Wilhelm Backhaus
From Backhaus's 1953 recital. Spontaneous prelude before playing the Chopin nocturne.
22:53 Dinu Lipatti
From 1936. Short improvisation on Bach-Busoni Toccata in C Major.