Historic moment in the Richie family last night -- Lionel shared the stage with his 14-year-old daughter for the FIRST TIME ... singing everyone's favorite song "Hello" ... and it was pretty awesome.
Lionel and daughter Sofia were at some think tank in Santa Monica called the Milken Institute when they both grabbed mics and broke into song.
Lionel told the crowd, "We have never done this in our lives. Never ever ever ever." It's pretty sweet.
If only we could say the same for Nicole Richie's music ...