During Sunday's Super Bowl, some viewers will tune in to watch every play by the Patriots and the Rams, while others might wait eagerly for the halftime show or the commercials. As it does at nearly all sporting events, "The Star-Spangled Banner" will mark the start of the proceedings - a dutiful and supposedly dull ritual. Unless it ends in disaster, it will almost certainly go unremarked upon by most viewers.

They would do well to listen a little more closely. This year, Gladys Knight will take on the notoriously difficult song, which is too often dismissed as a mere opportunity for famous musicians to showcase their vocal virtuosity. But as singers demonstrate every year, choices about how to sing the anthem convey a great deal about the particulars of the singer's patriotism. Nationalistic themes, of course, are built directly into the tune and its musical composition. There's still room, however, for the individual voice, and strategic musical decisions can turn a snoozer into a soaring aria that lifts spectators out of their seats.

The anthem demands that singers traverse a range of an octave plus a fifth, much larger than that of most modern pop songs, but less than the range of the 1970s Queen classic "Bohemian Rhapsody" and the same range as the 1980s hit "Take on Me" by A-ha. The final phrase ("And the home of the brave") elaborates on the opening notes but sets them a full octave higher, symbolizing U.S. ascent and triumph.

Singers need to start high enough that the beginning of the song ("Oh say, can you see") isn't too low for them, but low enough that, later in the performance, the ending won't be out of range. In 2011, Christina Aguilera was widely criticized for her Super Bowl performance, not only for singing the wrong lyrics at one point but also for the final notes, which lie too high for her natural range; she sounded like she was screaming them. She also didn't stay in the same key, indicating that she wasn't comfortable with the range and intonation.

Over the years, many artists - including Carrie Underwood, Luke Bryan and Idina Menzel - have sung the anthem at the Super Bowl unaccompanied. These performances tap into patriotic themes of individualism, self-reliance and bravery. But orchestrated arrangements of the anthem can be more grandiose and build climactic moments, especially at the song's conclusion.

Whitney Houston's classic 1991 rendition exemplified this approach. In Houston's version, performed just 10 days after the start of the Persian Gulf War, trumpets heralded her vocals over ". . . and the rockets' red glare," punctuating the passage and bringing it to life. She closed with a chord progression that led into a type of finale sometimes called a "Hollywood cadence." All musical phrases end in a cadence - a series of chords that close the piece and end in the home key - but the "Hollywood cadence" uses chords outside of the key to surprise the audience. This approach, which is similar to the end of the iconic Twentieth Century Fox intro music, prolongs and dramatizes the last notes of a song. For Houston, the Hollywood cadence coincided with the anthem's final word, "brave," giving her an opportunity to emphatically mark a moment of transcendence at the emotional height of the song.

Partly because U.S. audiences are so familiar with the anthem and partly because a Hollywood cadence is exciting, crowds intuit when a singer is taking this approach and often start cheering before the word "brave." Lady Gaga's 2016 Super Bowl performance drew massive audience applause at this moment. Music theorist Frank Lehmanwrites that the Hollywood cadence "drips with a sort of harmonic nostalgia," which is plainly evident when it's used at this point in the anthem: The chord progression alerts audiences to pay attention to the song's nationalistic final phrase. Several artists, including Mariah Carey in 2002 and Renée Fleming in 2014, have closed the anthem with a similar dramatic chord progression.

"Dreamgirls" star Jennifer Hudson, by contrast, put a jazzy spin on her 2009 Super Bowl performance, using swung rhythms and a drum set that sounded straight out of a jazz big band to personalize and differentiate her rendition. But when she got to the end of the song at "Oh say, does that star-spangled banner . . ." a military drumbeat also entered to call the audience to attention and close the anthem in a more traditional style.

One unusual attribute of the anthem is that, as Houston showcased in 1991, it can be reworked to fit different time signatures, or beats per measure. Typically the anthem has three beats per measure. In this setup, the song has one strong beat and two weaker ones in each measure, like a waltz: ONE, two, three, ONE, two, three. But Houston's arrangement had four beats per measure, shifting the emphasis so there were two strong beats. Four beats to a measure is the most conventional and popular time signature in general, but in this case, performers make the change to evoke order, like a battalion marching to war: ONE, two, THREE, four. Faith Hill's 2000 version of the anthem starts with a militaristic drum corps playing four beats per measure, then switches to the more traditional three beats per measure in the final section.

Some recent Super Bowl anthem performers have downplayed the militaristic grandeur in their arrangements. Lady Gaga in 2016 and Kelly Clarkson in 2012 each performed the song with three beats per measure and minimal accompaniment: Gaga with solo piano,Clarkson with a drum corps and a cappella backup singers. There was significantly less crowd noise during Gaga's performance until the big Hollywood cadence at the finish, reflecting her subdued version. While her rendition lacked the instrumental markers of patriotism, the bare-bones approachcalled attention to the lyrics themselves. Clarkson's version, meanwhile, took a more understated approach to its patriotic ethos: An angelic choir sang in harmony, accompanied by snare drums that subtly preserved the ordered march.

Sports fans have already begun to make prop bets on Gladys Knight's rendition of the anthem, speculating on the duration and whether she will forget any lyrics. But how will her "Star-Spangled Banner" match up to the musical details of previous performers? I suspect that she'll perform with a backing accompaniment track, as most singers have done in recent years. And while she'll probably sing with four beats per measure, I doubt that she'll rely on a drum corps. Instead, she'll probably offer an interpretation that aligns with her musical roots. Her tradition as a performer suggests that the anthem will be swinging and passionate, calling back to her musical style as the Empress of Soul.

Alyssa Barna has a master's degree in music theory from Indiana University and is a doctoral candidate at the Eastman School of Music.