Songs "Sung" in Silent Films:

Beautiful Dreamer
   1864. music and lyrics by Stephen Foster.
   in The Sheik (1921).
   What the lyrics on the title cards say Sheik Ahmed Ben Hassan
   (Rudolph Valentino) is singing under Lady Diana Mayo's (Agnes Ayres)
   window.
   See "Kashmiri Song" below.

Kashmiri Song
   1902. music by Amy Woodforde-Finden. lyrics by Laurence Hope.
   in The Sheik (1921).
   The song Lady Diana Mayo (Agnes Ayres) hears Sheik Ahmed Ben Hassan
   (Rudolph Valentino) singing in the book, The Sheik. I don't claim
   to be an expert lipreader, but Rudolph Valentino's lip movements in
   the movie seem to fit the lyrics to "Kashmiri Song" rather than
   "Beautiful Dreamer," as the movie's title cards say. My guess is that
   the filming was done according to the book, then in the editing phase
   someone decided to use a song more familiar to the audience.
 

Singing Silent Stars:

Buster Keaton
   Played the ukelele and enjoyed singing vaudeville songs in private
   with friends. He can be heard playing and singing in the documentary,
   Buster Keaton Rides Again (1965).

Wallace Reid
   Played the saxophone.

Pola Negri
   Sang a song called "Paradise" in the film A Woman Commands (1931).
   She also recorded at least one traditional gypsy song, "Why Be Sad,"
   with guitarist Boris Golovka and a gypsy chorus. This can be heard
   on the Pavillion Records CD, "Estrada: Russian Gypsy Singers,
   Recordings of 1905-1931" (GEMM CD 9960).
   Somewhere I remember reading that she played the guitar.

Rudolph Valentino
   His only record, with "Kashmiri Song" on one side and "El Relicario"
   on the other, was recorded at the Brunswick Recording Laboratories
   in New York on May 14, 1923. It was released by the Celebrities
   Recording Company, Hollywood, in 1926, after he was dead and helpless
   to prevent it. There's a good reason he didn't want this one to go
   public, although to be fair, the problems were mostly caused,
   directly or indirectly, by the technical limitations of the time.
   "Kashmiri Song," (see note above) sung in English (with a heavy
   accent; English was his fourth language, learned mostly as an adult),
   is from his film The Sheik. "El Relicario," sung in Spanish,
   seems to be about a bullfighter, as far as my limited Spanish can
   tell. Both were "oldies" when recorded, popular songs from the recent
   past, 1902 and 1918, respectively. These blasts from the past can
   be heard coming out of your very own computer speakers if you go to
   the Falcon Lair site, enter the doors, and check out "Valentino's
   Voice." The files require a plug-in that can play .rm (RealPlayer)
   files.
   One biography states that he learned to play the piano when he was
   a student at the Collegio della Sapienza. Unfortunately, the same
   biography makes some pretty wild claims about other aspects of his
   life, so I'm not sure how much it can be trusted.
   Still shots from show him holding a guitar in an expert manner,
   so he may have played, but then, he was also such a good actor
   that he could fake just about anything convincingly.
 

Songs Inspired by Silent Films or Stars:

Blood and Sand

   "You Gave Me Your Heart"
   1922. music by Ted Snyder. lyrics by Francis Wheeler and Harry B. Smith.
   Recorded by The Great White Way Orchestra.

The Sheik

   "The Sheik of Araby"
   1921. music by Ted Snyder. lyrics by Francis Wheeler and Harry B. Smith.
   Sung by Eddie Cantor in "Make It Snappy."
   It is said that Rudolph Valentino hated this song.
   In the 1950s Lou Monte recorded a comic novelty version in Italian.
 
Rudolph Valentino

   "There's a New Star in Heaven Tonight"
   1926. by J. Keirn Brennan, Irving Mills, and Jimmy McHugh.
   The dedication reads, "In Memory, Of Our Late Beloved Star."
   (Valentino died at the young age of thirty-one on August 23, 1926.)