CENTERING A DRAMATIC STORY on a love triangle is nothing out of the ordinary -- unless it's a musical that asks existential questions about insanity vs. genius, love vs. obsession and living an orthodox vs. unorthodox life.

Signature Theatre's world premiere of "The Highest Yellow" explores the relationship among Vincent van Gogh, a young internist and a prostitute. It is the Shirlington theater's first-ever commissioned musical. With an unusual score that relies heavily on songs about madness and love, the show is about the Dutch postimpressionist painter who bucks convention and a doctor who becomes obsessed with his patient's lifestyle and worldview.

Artistic Director Eric Schaeffer decided to commission the show five years ago because he was fascinated with van Gogh's life and wanted to portray the artist in a different way.

"The subject matter of van Gogh is very emotional and very passionate. . . . What's really exciting about this show is that the soaring melodies take you emotionally to places that so many times things in musical theater don't take you to," Schaeffer said. "This is not your typical musical theater. We're not doing 'Hairspray' or 'Mamma Mia!,' " he said.

Schaeffer brought together storywriter John Strand and lyricist-musician Michael John LaChiusa to create a two-hour-long musical that they hope will showcase van Gogh in the "highest yellow," a term adapted from the painter's writings in the provincial French town of Arles in 1888. In a letter, he described the sky there in technical terms as "chrome yellow, almost as bright as the sun itself, which is chrome yellow 1 with a little white, while the rest of the sky is chrome yellow 1 and 2 mixed. Thus very yellow."

In the show, van Gogh (Marc Kudisch) equates the essence of life to this yellow. When he sees it, he disappears into the exploding colors of the universe, in which he finds the utmost meaning.

When van Gogh's doctor, Felix Rey (Jason Danieley), meets his new patient at the show's opening, his supervisor says, "What if a man's illness were a source of his genius? Then to cure him would be a certain kind of death." The doctor begins to understand this as he gets to know van Gogh, whom he is treating for a "nervous condition" and a self-inflicted knife wound that resulted in a missing ear. Rey has long dreamt of leaving his small town for Paris and becomes so entranced with van Gogh's avant-garde outlook on life that he begins to imitate him, visiting a brothel for the first time and obsessively seeking a relationship with van Gogh's lover, Rachel (Judy Kuhn), who is a prostitute there.

Told through sometimes strange and sometimes humorous lyrics, the story makes a case for a creative thinker's unmedicated, unconventional approach to life, since it could lead to the kind of artistic greatness van Gogh achieved before his suicide in 1890.

It helps that those involved in "The Highest Yellow" relate, at least in a small part, to the primary question of whether a person's madness contributes to his genius.

"I think all of us as artists, we're all a little crazy," Schaeffer said. "To do what we do, we've got to be. But if you take that away, the art would never be what it is."

For if you take away "crazy" ideas, you might not have a musical about van Gogh, and characters wouldn't sing such lyrics as, "You need a touch of madness to be sane," "You need the dark to make the light / Lighter" and "The universe is nothing."

Signature Theatre's first-ever commissioned musical, "The Highest Yellow," explores a doctor's relationship with Vincent van Gogh (Marc Kudisch), the Dutch painter.