american-idol-top-4-harry-connick-jr“American Idol” has been scrimping on guest stars and mentors this season, but Harry Connick Jr. returned Wednesday to give the final four some tips and encouragement.

The last time he mentored, it seemed more that Connick wanted to plug his latest album, but this time he was genuinely concerned with the singers. So much so that he wanted to change the course of the competition single-handedly.

Over and over, he told the women that it would be better if they sticked to the original melodies on their song choices, be they standards or hits from today — the two categories this week — and skip all those runs and vocal flourishes.

Runs, of course, are what the competition is all about. Mariah Carey, inarticulate as she is, is on the judges panel as if to ensure those vocal runs are in place. Yes, they’re often over the top, and no, they’re not really needed, but, to quote a phrase the judges trot out this time of year, “at this point in the competition,” it’s about the only thing they have to make themselves stand out.

Singers who got Connick’s advise nodded and agreed off camera that he was right. But when it came to the live performances: Run city.

This was the second straight week of the final four after what was touted as a “surprise twist” last Thursday when Ryan Seacrest, after making the poor girls worry on camera all night, said that the person going home was the same person who’s been watching “Idol” all this season: Nobody.

It wasn’t a surprise, of course, for anyone doing the math. Because judges didn’t use their save, there was an extra week built in between now and the finale to kill time. Hey, “The Amazing Race” has non-elimination pitstops all the time to make those adjustments (on the other hand “Survivor” had two tribal councils Wednesday to better even out its numbers before its own finale).

With the four back to sing, you’d think they’d be relaxed and having fun, but all of them seemed especially nervous and held back some on the first half of the night, the current hits. As a result, judges were reserved as well. None stood to applaud and some were openly critical.

Angie Miller’s opening version of Rihanna’s “Diamonds,” all deconstructed and done on the piano, as the judges love, was “bland and lackluster” Nicki Minaj said. Randy and Keith agreed that it didn’t go anywhere.

Amber Holcomb did a pretty good job swinging on Pink’s “Just Give Me a Reason,” but looked pained throughout. Randy said it wasn’t stellar.

But Candice Glover’s version of Bruno Mars’ “When I Was Your Man” was a killer, so heartfelt it didn’t matter that she didn’t change the gender of the title. “I don’t care if it was ‘When I Was Your Giraffe,’ ” Keith Urban said.

Kree Harrison sang a strong version of Carrie Underwood’s current single “See You Again,” which she sang on the show a few weeks back. Judges generally liked it, though Keith said it was odd that all we could see was her and the guitar player sitting down and not the band swelling to a big moment behind them.

The second half, standards, brought out some beautiful songs, the first of which was “Someone to Watch Over Me” for Angie Miller, who said more than once in her filmed piece that it was a song her mother often sang, but still Keith asked her shy she was doing it.

Randy was right, though, the arrangement was a mess. And when Mariah tried to make a point that contradicted something someone said earlier, Nicki had this whole argument saying she should clean out her ears, and even pulling something out of her purse to enable her to do so (an eyebrow pencil?).

The women shouldn’t fight in front of Ryan, though; he gets insecure.

Amber’s classic was a version of “My Funny Valentine” that had wowed judges earlier in the cometition. Her version Wednesday was even better, earning the judges’ first standing ovation of the night. This after Connick humiliated her on film when he kept asking her if she knew what the lyrics meant.

Amber was in tears after the performance not because of that, nor because of happiness, but because she was worried that even though she could have the stellar performance of the night, the votes at home wouldn’t be there with her. She’s been in the bottom two or three three times out of the last seven weeks.

It’s important to remember that Amber was in the bottom two last week with Candice Glover — arguably the two strongest voices of the season. So voters don’t know what they’re doing and Nicki is right: It doesn’t matter who wins Idol, because all four have an equally strong chance of having solid recording careers.

For her standard, Candice chose a great one, Billie Holiday’s “You’ve Changed,” and it was one of those times Connick argued that she should do it straight. She added a few flourishes and runs, though, and it still turned out great.

The argument continued through Kree Harrison’s standard, “Stormy Weather.” Connick insisted that she stay on the melody and demonstrated on piano how crazy the song with runs sounded to people. Still, Kree bent her notes and the judges began to carp not only on song selection, but also whose version she should have been modeling after, Lena Horne or a more bluesy one.

The argument could have continued, since they spent the final minutes of the two hour episodes doing a wholly unnecessary and crazy group song, “Wings” by Little Mix, who were the eight season winners of “The X Factor” in England — a case of cross promotion.

Whoever gets the least votes from this week (mixed with last week’s votes) will be sent home, but so will the three survivors: They’ll go home for the traditional homecoming episode, which it seems to me used to occur much earlier in the season. Cheaper to send three home rather than four or five.