"He's one of the (most) incredible songwriters of all time and I can't believe I'm actually about to perform with him. We're going to do one of my favourite songs of all time. It was my go-to song to sing at a gay bar, a karaoke bar... anywhere. So I'm actually going to get to perform it with him right now. This is such a surreal experience." Ariana Grande introduces songwriter/composer David Foster to the stage during her show at The Forum in Los Angeles on Wednesday (08Apr15). She performed I Have Nothing, the song he co-wrote and produced for Whitney Houston, with Foster.