There are no definite steps in how to write a song. A song can be written by someone who is new to music and by someone who knows how to play instruments very well. The difference is the technicality of the song produced. It is easier to write songs with an accompanied instrument during the process, most often a guitar or a piano. Here are some steps to follow.
The first step is to learn what to write about. It is important to have an idea on what the song is about. There should be a vision before anything is started on. Knowing what a song is about defines the mood of the song and sets standards to how it will sound like or what the lyrics would focus on. Take note, there are genres like rap wherein some songs are written because it is an answer to a political movement, or like country music wherein some songs are written to tell stories and experiences.
The second step is to determine the chord progression and the melody. Since there is a focus on what the song would be about, it is important to know how it will be played. It can use the same chords throughout, or it can use different chords for the different parts of the song. A song usually has verses, a chorus and a bridge. Know how long the chord stays before it changes to another, or how the chord is played. Play it in different ways until the desired result is acquired. For example, a sad melody normally uses chords from the minor scale.
The third step is to determine the work needed to be done. For a song with lyrics, once the chord progression and the melody are done, the songwriter can write the lyrics to the song. Words have a natural rhythm in how they are pronounced and enunciated. It is important to take note of the message of a song and how it all comes together. For instrumental songs, pick up a new instrument. Listen to new music. It is important to learn or refresh with music theory and experiment with new sounds and instruments. Do not be afraid in trying out new things while making music. While there are certain expectations due to the genres of music, it is important to remember the need to experiment and put things together to know if certain things can work together or not.
The fourths step is to keep distance. The problem with working on a song is the need to play it repeatedly. Sometimes too much exposure to the same music blinds the judgment. While it is essential to look through everything underneath a microscope, it is also important to take breaks and allow the song and the mind to rest.
The fifth step is to improve and then move on. Ask a friend or a music enthusiast for thoughts about the song. It is important to listen to other people and improve the composition. However, it is also important to learn when to detach from a song and move on.
Observing these simple steps can be very helpful in writing a song. It also makes it easier to really feel, understand, and relate to the theme of the composition for it to come out more naturally.