When an instrument is out of tune, adjustments are required. When a life is out of tune, adjustments may also be necessary.

In “A Late Quartet,” a fine melodrama about a renowned string quartet preparing for a 25th anniversary concert, we see a group that is still making beautiful music together.

We also see how fragile that artistry — and the sort of family these people have formed — can be when the music stops.

The Fugue String Quartet has been in tune with one another for a generation. In the world of chamber music, this New York-based outfit is something of a legend, and their plan to perform Beethoven’s Opus 131 — a 40-minute effort with seven movements to be played without pause — is eagerly awaited by fans.

When one member learns that he may not be able to continue due to health concerns, the shift in power — with people going from thinking about the good of the group to thinking about their own self-interests — is striking.

Eclectic casting helps make what might seem like a niche film as to audience interest feel more universal.

On first violin is the strict, precise Daniel (Russian-born actor Mark Ivanir is the film’s standout); on second violin, adding harmony, is Robert (Philip Seymour Hoffman); on viola is Robert’s wife, Juliette (Catherine Keener); and on cello, the group’s bonding force, is Peter (Christopher Walken).

It is Walken’s character whose failing health precipitates the drama to come, and he beautifully plays the forlorn widower’s concern that if medication does not ease his early stages of Parkinson’s disease, the group may dissolve.

So time is of the essence. Time is always on the mind of writer-director Yaron Zilberman. Through his very interconnected characters he explores the time of the present as well as the past among these longtime friends. He demonstrates as well as the ideas of how music depends on time.

The egos of the other players induce selfish decisions for which there can be but one reaction: Your timing is awful.

We are drawn into this dysfunctional family easily because it’s so much more than a husband and wife. Peter was like a father to Juliette, who was close to Daniel in college; Daniel is the violin teacher (and maybe something more) to Alexandra, the daughter of Robert and Juliette; the group was formed when Daniel invited Peter to join.

While the emotions run high (and Ivanir is a wonderfully fiery match for Hoffman’s display of emotions), the film is underscored by a gorgeous soundtrack. Music by Angelo Badalamenti combines both pain and beauty in its sounds and intrinsically complements the works of Beethoven.

It will take someone more aware of chamber music than myself to tell if these actors are convincing from a visual standpoint as musicians (the sounds are actually created by Bretano String Quartet) in performance mode.

Where the stars truly shine is in demonstrating the process of musicians. The way that they talk about music and disciplined practice translating into performance makes up for some of the soap-opera moments that go too far.

It is similar to actors talking about their own craft in an intelligent manner, and it’s a fascinating look inside the music.