The third verse of "Mmm Mmm Mmm Mmm" by Crash Test Dummies ("they shook and lurched all over the church floor...") was inspired by girl whose parents would speak in tongues at their Pentecostal service.
Will.I.am, literally dreamt up "I Gotta Feelin'." Said the Black Eyed Pea: "Have you ever had a dream where there's a melody in your dream? I'll wake up out of my sleep and record that! 'I Gotta Feelin' was one of those songs."