Michelle Williams and Dietrick Haddon will be serving some honest truths to gospel choirs across the US in their reality TV show, Fix My Choir.

The show premiered last night on the Oxygen network and saw the Destiny's Child and Preachers of LA stars offer some of their expertise to New Orleans group Joshua Kagler & Harmonistic Praise Crusade.

The name of the group may suggest these guys sing along together great, but the reality is a little different, and Williams and Haddon had to work them from the ground back up again to find their true harmony ahead of a "reveal" concert at the end of the episode.

Williams said in an interview with Nola.com she got more than she bargained for in taking on the show.

"The thing about 'Fix My Choir' is, when I got the show, I thought I'd just be helping somebody with performance tips, hair-and-makeup ideas and wardrobe," she said.

"But we're literally like Dr Phils for choirs. We're coaches, mentoring. It goes beyond their performance in the music."

Haddon said he was in his "element as a pastor" working through the challenges with the different choirs.

"I'm always seeking opportunities to help people and encourage people and motivate them to be the best, so I was in the zone dealing with that. The show gave me the opportunity to be the pastor that I am and operate in my calling," he said.

Part of their work with the struggling choirs inevitably involved delivering some difficult home truths and the two stars were aware of the need to say it in the right way. 

Haddon told Eurweb.com: "How you say it to them can mean everything because you want to keep them inspired, even though you're telling them the truth when you tell them they can't sing." 

Williams said: "It's all in how your delivery of the truth is." 

Watch the trailer for Fix My Choir below: