“When you’re singing a song that is so well-known as ‘How Deep Is Your Love,’ you need to stay with the melody,” straight-shooter Reba warned Mac Royals. But he totally ignored her advice.

Reba McEntire warns Mac Royals and Rachele Ngyuen to repsect the Bee Gees during their Battle Rounds rehearsal on ‘The Voice.’ (NBC)

The Voice Season 24 Battle Rounds continued apace Tuesday, and when two of Reba McEntire’s contestants, crooners Mac Royals and Rachele Ngyuen, were assigned “How Deep Is Your Love,” Mac described the Bee Gees’ Saturday Night Fever end-credits ballad as “one of the most iconic and beautifully written songs of all time.” And that was not hyperbole. The song really is that perfect.

So, it made absolutely no sense when Mac then audaciously and somewhat blasphemously decided to stray far from the song’s beloved melody, so that he and Rachele could “give the people a little of what we do and what we like.” Reba, who is proving to be a refreshingly real straight-shooter this season, was quick to shut that strategy down during rehearsals.

Or, at least, she tried to shut it down.

“Mac, I didn’t think you were hearing the beat. You kind of went in a different direction on it,” a mildly perturbed Reba observed, as she wisely warned both singers not to change up the classic tune too drastically. “The reason we pick the songs we do is because of familiarity. … [Fans] want something they can sing along to. When you’re singing a song that is so well-known as ‘How Deep Is Your Love,’ you need to stay with the melody [viewers] remember, so [they] can sing with you and be a part of the show.”

Mac nodded in seeming agreement, so I still expected the buttery-voiced busker-by-day to excel over less experienced teenager Rachele. But honestly, neither of them did the Bee Gees’ classic much justice. Their vocals didn’t blend well, despite Reba pairing them because they were both from the “R&B space.” Rachele’s off-the-rails wailing was try-hard and cloying. But, most vexingly, Mac was constantly singing behind the beat, against his coach’s clear wishes, presumably on purpose in an attempt to make the song his own.

After their Battle Rounds performance, tough-lovin’ Reba was quick to chastise Mac onstage for his questionable artistic decisions, bluntly stating: “Mac, I still wish we could have stayed with the Bee Gees’ version of the opening, because that kind of threw me again — as it did in our rehearsals.”

Reba ultimately chose Rachele, who at least tried to take direction this week, but John Legend surprisingly stole Mac, explaining that Mac has “the kind of voice I love to listen to, right in my wheelhouse.” But really, if any performance should have been montaged Tuesday, it was this one. Instead, four other singers from John’s supposedly stacked team had their Battles inexplicably edited down to mere blink-and-you’ll-miss-‘em seconds.

Here’s how the rest of Tuesday’s Battles — the good, the bad, and the montaged — played out:

TEAM NIALL: Nini Iris vs. Sophia Hoffman, “Heart of Glass”

Nini turned four chairs at her Blind Audition, while returning contestant Sophia turned no chairs when she tried out in Season 23 last spring. So, this Battle definitely seemed like a Davey/Goliath situation. There was also the legitimate concern, which Niall Horan voiced, that Blondie’s Studio 54 floor-filler “could easily turn into a karaoke song” if either contestant didn’t nail the right rock ‘n’ roll vibe. Niall didn’t need to worry about that at first, because the intro’s slowed-to-a-crawl, almost gothic arrangement was markedly different from the 1979 original. But once the house band’s wocka-wocka hustle beats kicked in and the girls started bouncing and bopping around, their disco performance did veer into drunken-bachelorette-party territory. Nini ultimately elevated the moment with her raw charisma and theatrical presentation; in other words, Goliath won this Battle. Niall thought both women “sang the roof off this place” and hoped one of the other coaches would swoop in for the Steal to alleviate his guilt, but this round was the last dance for Sophia.

WINNER: Nini Iris

TEAM GWEN: Calla Prejean vs. Chechi Sarai, “I Will Never Love Again”

These two pop/R&B powerhouses were assigned Lady Gaga’s mighty A Star Is Born weeper, which proved to be a challenge for poised perfectionist Chechi. “Stop trying to be a singer, and start trying to be a person that we want to get to know,” Gwen Stefani gently but wisely scolded her. Thankfully, Chechi took that direction, allowed herself to be vulnerable, and proceeded to dominate this duet, using her potentially gimmicky Minnie Riperton-esque whistle notes to great effect while still maintaining connection throughout. Meanwhile, Calla’s attempt to heed Gwen’s advice about creating smoother transitions between dynamics didn’t work out quite as well; John even described Calla’s approach as “unsure.” And so, a star was born tonight, and that star was… Chechi.

WINNER: Chechi Sarai

TEAM LEGEND: Talakai vs. Caleb Sasser, “Too Good at Goodbyes”

Talakai received a lot of screentime during the Blinds because he looked so much like his coach John’s long-lost twin, but apparently the “family resemblance” didn’t given him any nepotistic advantage this week. He must not have been too good at singing “Too Good at Goodbyes,” because this performance was ruthlessly montaged. John instead went with Caleb, whose tone he described as “intriguing and mysterious.” I’m just intrigued by the mystery of what really happened with poor Talakai.

WINNER: Caleb Sasser

TEAM LEGEND: JaRae Womack vs. Lila Forde, “Killing Me Softly”

This montage was another big mystery. John has seemed like the coach to beat all season, with eight of his 14 contestants being four-chair turns — and I totally expected one of those four-chair standouts, who also happens to be a member of R&B royalty, to get plenty of screentime this season. But actual nepotism didn’t work here either. Bobby Womack’s niece, JaRae, was only fleetingly shown Tuesday harmonizing with her opponent and this Battle’s ultimate victor, Lila Forde, who John said possessed a “unique magic.” And then, JaRae magically disappeared.

WINNER: Lila Forde