Complex sentence: Lovato enlisted Rooney frontman Robert Coppola Schwartzman for the track "Party", stating that she put her "musical input and lyrics" into the song and Schwartzman helped her, mainly on the hook.
Split into simpler sentences: Lovato enlisted Rooney frontman Robert Schwartzman for the track "Party". Lovato stated that she put her "musical input and lyrics" into the song, and Schwartzman helped her, mainly on the hook.