<P> Once the series of chords is selected, additional lines are added to the piece . The most important part in many genres is a lead melody line . This melody may be supported by one or more harmony lines . Songs often have a bassline which adds to the identify of the piece . Popular music is often written this way (see: Song structure) where a selected series of chords forms the structure of each of a particular section of the song (e.g., verse, chorus). The melody line is often dependent on the writer's chosen lyrics and can vary somewhat from verse to verse . </P> <Table> <Tr> <Td> </Td> <Td> This section possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (November 2016) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This section possibly contains original research . Please improve it by verifying the claims made and adding inline citations . Statements consisting only of original research should be removed . (November 2016) (Learn how and when to remove this template message) </Td> </Tr> <P> Another way to compose music is to start by creating a melody, melodic theme, or group of melodies . Once these melodies and themes have been created, the composer can then add suitable chords which will support this melody . The same melody can be supported with many different chord progressions . For example, if a songwriter has a song in the key of C major in which the melody begins with a long "G", this melody note could be supported with a tonic chord (C major), a dominant chord (G major) or a mediant chord (E minor). If the song is written in a jazz style, this held "G" note could be supported with a secondary dominant chord (e.g., an A7 chord, in which the "G" is the dominant seventh of the chord, which could then resolve to a D minor chord), or even by treating the melody note as an "extension" to an existing chord (e.g., supporting the long "G" note with an F Major chord, thus making the "G" note the added ninth of this chord). </P>

An instrumental piece of music consisting of a set of