AJ McLean Pays Tribute, Dedicates 'Building the Band' to Liam Payne

Liam Payne's passion for music and impact on "Building the Band" will be felt on the new show ... this according to Backstreet Boys star AJ McLean.

The singer-songwriter -- who is hosting the show -- opened 'BtB' with a heartfelt tribute to the late One Direction star ... saying they never thought they'd be saying goodbye to him so soon.

LP appears as a guest judge in later episodes -- which will be released several at a time over the next few Wednesdays -- and, McLean says his love of music and commitment to helping contestants find their voices will be evident.

McLean then dedicates the series to Payne and his family before the ep begins in earnest.

As you know ... Liam fell to his death from a hotel balcony in Argentina in October 2024. Authorities said he had "pink cocaine" and "cristal" in his body when he died.

In the aftermath of his tragic death, Netflix announced he would appear in the show. While it wasn't clear if they planned to shelve the show, it seems they ultimately took the opportunity to honor Liam through his work.

Nicole Scherzinger of Pussycat Dolls fame also appears on the show ... and, she shared a heartfelt message just after Liam passed -- referencing their time on the show in an Instagram post by saying, "It was such a blessing to get to work with you recently."