A song is a piece of music that contains both lyrics and a melody. It can be a musical composition created by humans, like the famous Happy Birthday song, or it can be folk songs that were passed down through generations. It can be played on a piano, guitar, or even just in the voice of a human. Many bands make their living writing and performing songs. When two or more people sing together, it is called a duet or trio. When someone changes the words of a song but keeps the tune, it is called a parody (think “Weird Al” Yankovic).
A bridge is a part of a song that often has different lyrics from the verse and chorus. It may also have different music than the other sections of the song. It is common for a bridge to contain the title of the song and be shorter than the chorus.
Learning about some of the common components of songs can help you write more interesting melodies and riffs. Having a basic understanding of how these parts of a song work can also help you avoid making mistakes that will make listeners yawn and close the window on your new creation. In addition, some song forms are used heavily in particular genres of music, so developing an awareness of both historical use and current usage trends can help you select the most appropriate song form for your specific goal.