The biopic poses any filmmaker with a great challenge. How do you capture the essence of a great human being in the span of two hours? One method often employed (though often to lessening degrees these days) is the heavily-criticized "Cradle to Grave" which shows the entirety of the hero's life while showcasing his/her greatest hits along the way.

A more common method is to pick a major event and attempt to open a window into the person's life through this moment. Hence the recent "Steve Jobs" movie.

Now what of Miles Davis, a musician known for his revolutionary status; a man who defied convention, demanding that he not be classified as an artist of a particular genre; a man who moved from acoustic performance to electronic when it was not considered kosher. How do you define that essence in a movie?

Don Cheadle's "Miles Ahead" has come a long way toward completion, even needing an Indiegogo campaign to finish acquiring all of its financing. The director/actor/writer of the film seemingly decided that for an artist with such an expansive vision, a film that also defied genre convention was necessary.

The film is set across two periods of Davis' life. The first is during his "Silent Period" when the artist took a long hiatus from performing and recording. The other showcases him during his glory days and the start of his romance with Frances Taylor. The "Silent Period" narrative, which is more or less a fiction in which Davis tries to recover stolen recording tapes, poses a major question that the latter sequence attempts to answer concurrently -- why did Davis stop his performances and become a bitter recluse?

Interestingly, there is never truly a satisfying answer to the question though narratively the two "plots" show the character progressing emotionally from opposite states. In the opening of "Silent Period" is a lonely, angry man ready to punch some random reporter who shows up at his home asking for an interview. The earlier period shows him performing with a band; he is clean-cut, well-kept and in the "peak" of his performing years. Yet the clean-cut man will slowly turn into the violent and aggressive misanthrope while the lonely remnant of the iconic figure will slowly but eventually find his artistic fire once again.

Cheadle's film style is initially rather off-putting with the camera seemingly trying to find a focus on the character, but constantly moving away from it. And the narrative threads initially move about with a sense of improvisation, a visual portrayal of jazz. Eventually the film language becomes more traditional and the narratives move about. The two narratives are actually rather different in feel and tone. The relationship with Taylor is almost dream-like, moving and flowing with no real sense of direction. The "Silent Period" sequence feels more like a buddy movie with fictional reporter Dave Brill tagging along to recover the records. It has a slapstick feel at times and, while entertaining, does come off as artificial with its over-emphatic gestures. The ending of the "Silent Period" sequence does bring about a unique twist, reminding everyone that this man is truly difficult to pin down. As the film draws to an end, Cheadle showcases a performance sequence featuring some of Davis' key collaborators onstage in a moment that exists out of a time, a reminder that the artist lives on ( this is emphasized by a title card showing the dates of Davis' life but not showing the true date of his passing).

The film's opening and closing sequences are shot in a digital format, which contrasts heavily with the grain of the middle narratives.

Cheadle is terrific as Davis, managing to create his iconic raspy voice perfectly. Much of the performance in the "Silent Period" sees the iconic musician in sunglasses, yet Cheadle, with his physicality, is able to express the drive and energy of Davis.

Ewan McGregor stars as Brill. He is in every single scene in the "Silent Period" sequence and yet his presence is rarely felt. Unfortunately this comes down to two factors. Cheadle steals the show as Davis (as he should) and Brill is little more than a plot device in the movie. He is the inciting incident and sets the plot in motion, but most of the time he does things unintentionally. He gives Davis a person to talk to but we know nothing about him that makes him a memorable character. McGregor does his best with the material, hitting the one-liners rather well, but it does not amount to much.

Emayatzy Corinealdi is an alluring presence as Taylor and shows herself to be a strong counterpart to Cheadle's aggressive Davis; she wins over the allegiance of the viewer during their big argument scene.

Michael Stuhlbarg is a one-note greedy producer while Keith Stanfield's shy junior provides a nice counterpart to Davis' more extroverted nature.

"Miles Ahead" reaches high with its subject matter and genre subversion. However, the catharsis never comes. The sense that Davis is this revolutionary genius is never truly felt; the audience is constantly reminded of his greatness by other characters onscreen, but the sense of his artistic importance is glimpsed over in a few performances. People that are familiar with the artist will undoubtedly connect with the narrative, but those unfamiliar will come away wondering what the hype was all about.