Adam Lambert has never been shy about expressing his opinions, but on Tuesday night, the season-eight [article id="1636059"]"American Idol" runner-up provided some of the most candid and spot-on advice[/article] of any mentor in the show's history.

While previous mentors have typically offered sweet nothings, praise and light advice to the contestants, like [article id="1635110"]another season-nine guide, Usher[/article], Lambert dug in and really encouraged the singers to push the envelope and display their personalities, providing concrete suggestions for molding their performances.

He was unafraid to criticize their choices -- counseling Andrew to punch up his version of "Hound Dog" and loosen up a bit and suggesting to Siobhan Magnus that her arrangement of "Suspicious Minds" needed to be sped up a bit to really pop -- and praise them when they made the right ones. The results didn't always translate into great performances, but Lambert's efforts drew praise from no less an expert than [article id="1636117"]outgoing "Idol" musical director Rickey Minor[/article].

"From the first day I met Adam in Hollywood Week -- and he stood out right then -- I've always thought he was someone to listen to," Minor told MTV News on Wednesday, the day after it was announced he'd be [article id="1636068"]leaving "Idol" at the end of this season for "The Tonight Show."[/article] "This is a visual art as well, and I think he did really well, because he's been in the competition and he's in their age range. It's not like some star who's been around for 30 years saying, 'You need to do this.' Adam can say he was on the show last year, and he knows how it feels. It was a great idea to have him on."

Minor said Lambert's honesty and truthfulness with the contestants, both good and bad, was refreshing. "He was the one who told them, 'No one told me I'd be working 10 times as hard [once I left the show],' " Minor said. "His thing was to challenge them, and I have a lot of respect for him having already worked with him. And now that he's come in and talked to these kids, it's even bigger."

Close "Idol" watcher MJ Santilli, who runs MJsBigBlog.com, said she would have preferred that an "Idol" elder like Carrie Underwood or Kelly Clarkson be the first former contestant to return as a mentor. "But having said that, I think Adam did a fine job," she said. "He's got something many of this year's contestants lack: the ability to craft a performance that's vocally, visually and emotionally stunning."

With that unique combination and his no-nonsense attitude, Santilli said Lambert's suggestions to the nine finalists was refreshing. "Coming from that perspective, Adam was perfect," she said. "He gave the kids good advice on how to make their performances more exciting. Adam's an articulate guy who expresses himself well. He was honest and constructive."

In fact, on a night when the four panelists often agreed in the same bland way or disagreed on minor points, Santilli said Simon, Kara, Ellen and Randy "might want to take a few pointers from [Adam]."

How did you think Adam did as a mentor? Sound off in the comments below!

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