Lyric setting is the process in songwriting of placing textual content (lyrics) in the context of musical rhythm, in which the lyrical meter and musical rhythm are in proper alignment as to preserve the natural shape of the language and promote prosody.
Prosody is defined as "an appropriate relationship between elements." According to Pat Pattison, author of Writing Better Lyrics, prosody is created when all musical and lyrical elements work together to support the central message of a song. To achieve prosody, the rhythmic placement of a lyric in music must support its natural rhythm, meaning, and emotion.