If the definition of insanity is doing the same thing over and over and expecting a different result, then surely Hanon etudes are a ticket to the madhouse.

This week on “Picture Perfect,” get keyed-up with music from movies about madness and the piano.

Whenever he hears a loud, discordant sound, unhinged pianist-composer Laird Cregar is compelled to commit murder, in the 1945 film “Hangover Square.” Bernard Herrmann wrote the moody, romantic score, which includes a piano concerto, played by Cregar’s character during the film’s conflagration finale.

Peter Lorre is an unstable musicologist who is haunted by the disembodied hand of a murdered pianist with a penchant for Brahms’ arrangement of Bach’s Chaconne, in “The Beast with Five Fingers,” from 1946. Max Steiner was the composer. The piano is played on the film’s soundtrack by Victor Aller, the brother-in-law of Felix Slatkin – also Leonard Slatkin’s uncle.

Alan Alda plays a frustrated pianist who falls in with a ring of Satanists, in “The Mephisto Waltz” from 1971. This time, Jerry Goldsmith blends Franz Liszt with amplified instruments and electronics to memorably eerie effect. Five years later, Goldsmith would win his only Academy Award for his music to “The Omen.”

Finally, Hans Conried plays a dictatorial pedagogue in “The 5000 Fingers of Dr. T,” released in 1953. “5000 Fingers” holds the distinction of being the only feature ever written by Dr. Seuss. The film sports an outrageous production design (including a gargantuan keyboard for 500 enslaved boys) and whimsical songs.

The composer was Frederick Hollander. Born in London, Hollander attained fame in Germany as Friedrich Hollander. His best-known international success was “The Blue Angel,” starring Marlene Dietrich, who introduced his song, “Falling in Love Again.” With the rise of the Nazis, Hollander fled to the United States, where he worked on over 100 films.

That’s music from movies about madness and the piano this week, on “Picture Perfect.” Practice makes psychotic, THIS SATURDAY EVENING AT 6:00 EDT, on WWFM – The Classical Network and wwfm.org.