Awards shows have also gotten increasingly political, with celebrity presenters and winners playing the role of firebrands at town-hall meetings. The Grammys, which are broadcast on CBS, were no different on Sunday, with several performers bringing up immigration and the #MeToo movement. U2 performed on a barge just outside the Statue of Liberty, a performance not exactly subtle in its symbolism, and Hillary Clinton showed up in a taped segment, reading about President Trump’s preference for McDonald’s food from Michael Wolff’s best-seller, “Fire and Fury: Inside the Trump White House.”

Nikki R. Haley, the United States ambassador to the United Nations, gave voice to proponents of the “shut up and sing” side of the debate. “I have always loved the Grammys but to have artists read the Fire and Fury book killed it,” Ms. Haley wrote in a tweet during the event. “Don’t ruin great music with trash. Some of us love music without the politics thrown in it.”

TV executives have also suggested that viewership is cyclical, largely depending on whether there are blockbuster movies to promote or superstar singers set to perform. Analysts have also suggested that in the world of streaming, long telecasts packed with commercial breaks — the Grammys lasted a little more than three and a half hours — are a much harder sell for TV viewers these days.

There are also more digital distractions than ever. HQ Trivia, the live streaming smartphone quiz app, said it had 1.6 million players on Sunday night, a record for the game, which went live about an hour and a half into the Grammys telecast.

Between 2013 and 2017, the Grammys’ ratings fluctuated between 26 million and 28 million viewers, good enough to make it the second-most-watched awards show, behind the Academy Awards.