By Alyssa Rosenberg / The Washington Post

Ideally, when you learn that a beloved actor has died, your thoughts would go immediately to their most important and memorable work: the performance for which they won an Oscar, or with which they created an archetype or helped clarify an important social issue. But when I heard that Martin Landau had died, my mind flashed immediately to “Entourage,” HBO’s mostly unloved sitcom about the entertainment industry, which ran from 2004 to 2011.

Sometimes you can measure an actor’s skills by how much work they put in on a derided project, and their ability to elevate middling material.

On “Entourage,” Landau played Bob Ryan, an aging Hollywood power player desperate to stay in the game. At the time the series was on the air, there was some speculation that the character was based on Robert Evans, a producer of movies like “The Godfather” and “Chinatown” and author of the memoir “The Kid Stays in the Picture”; Evans had been approached to play a version of himself on the series and declined. But even given those circumstances, Landau managed to make the Bob Ryan character his own, an anachronism in a rapidly evolving business that illustrated both the industry’s new polish and its occasional lack of honor.

Bob Ryan was an old-fashioned man who sports blue blazers and slacks at a moment when younger men are wearing slouchy casual-wear or adopting sharply tailored suits. He lives in the sort of formal style that Hollywood’s hyper-wealthy didn’t aspire to, even in the early years of this new century, with drivers, butlers, maids and ostentatious chauffeured cars. Ryan’s movie pitches were hokey and dated, frequently ending in the question “Is that something you might be interested in?” He could be a fossil, an embarrassment, and on a show that was so comfortable being cruel, Ryan could have easily been a mere joke.

Landau, like many of the supporting actors on “Entourage,” defied that possibility, bringing a wounded dignity to the part. Landau gave Ryan a sharp tongue and a sensitive ear to insult; the character was self-aware enough to know that while he had produced great movies, he was perpetually in danger of being ignored and condescended to. Ryan was old enough that the prospect of utterly reinventing himself for a new industry was too daunting to be considered. But just because he was stylistically out of step didn’t mean his taste had failed: The script about the Ramones that he had on offer was genuinely strong.

Watching Landau juxtapose Ryan’s melancholy when he revealed to a young movie star (Adrian Grenier) that he was profoundly lonely with Ryan’s enthusiasm when he realized that someone else shared his passion for that script wasn’t just a good performance about the creative process. It was a nice bit of acting about what it means to age, to fear being forgotten and to recognize that you may have one last shot at relevance and the feeling of connection that comes with continuing to work.

The character of Bob Ryan doesn’t make “Entourage” a great show, any more than the presence of terrific female characters such as studio executive Dana Gordon (Constance Zimmer) or publicist Shauna (Debi Mazar) made up for the series’ constant ogling and parade of dumb hotties. But it was a nice little metric of Landau’s ability to give a character a distinctive walk, to let cantankerousness melt away to reveal pain and a reservoir of excitement. It’s wonderful when pop culture gives actors terrific material; it’s also worth recognizing when actors improve everything they touch.