What is commercial music?

assist musicians to craft music that is commercial.
Questions and debates arising though are:

What is a commercial song?

Who determines what is commercial?

What is the formula used in making commercial music?

Is there music that is not commercial?

Funny enough what I like may not be what you like and so how at least do we disqualify one song from the other and yet the same song has an audience.
Some other interesting questions that need to be answered, are:

Does it mean that the songs that are currently topping the charts are what people would sacrifice their hard earned dollar to buy?

Slow songs are not commercial in their nature, only fast and catchy songs sell, is this true?

While there is no absolute “right” and “wrong” when it comes to songwriting, there are certain factors which tend to increase the likelihood that your song will appeal to a wide audience and become a hit and you may enjoy commercial success.
I don’t believe that their is a “formula” for creating hit or commercial songs. The truth is that commercial songwriting is both an art and a craft that takes talent, study, and lots of practice.

Through research you will find that there are certain characteristics that should or can help to guide your song to becoming commercial, and below are a few hints.
People or deejays will buy or play songs that make them feel something they want to feel. Everyone likes to feel happy, which is why so many love songs and fun dance songs become hits.
They also like to have the comfort of knowing that sad or painful experiences they’ve had in their lives are shared by others, which is why we hear so many songs about lost love and loneliness.

People don’t want to be depressed, though, which is why most sad songs that become hits include a ray of hope that the singer will somehow deal with the pain and that things will get better.
Audiences usually don’t want to be preached at or have fingers pointed at them.
The most successful message songs are ones that tell a story that draws the listener in, and then leads the listener to draw his own conclusion.

A perhaps unfortunate reality of the music business is that it is a business, and most international record companies spend money to create a product that they think is likely to make a profit.
If you love to write Ethiopian drum music, for example, you should take a look at the market for Ethiopian drum music to assess your chances of getting your material recorded and played on the radio.
If there are no radio stations playing that kind of music, then it’s going to be very difficult to have a hit in that genre.

Markets do exist for even the most obscure types of music, so if that’s your passion, seek out those markets and promote your music there, but realise that the amount of money to be made is likely to be modest.
Hit or commercial songs are usually songs that are easy and fun to sing along with. This means a strong, catchy melody, and a structure that provides a balance of variety and repetition.

Structure is important because it gives the audience something to grasp onto. It allows them to be involved in the song.
It allows them to remember the song and hum it in their heads. If there are too many sections, or if there’s no logical flow from one section to the next, most people won’t be able to follow the melody, and they’ll lose interest. On the other hand, if your melody is too predictable, it will probably be boring. Song structure helps create interest by creating natural points within the song for melodic contrast.

People will relate better to characters and situations that come across as real and believable.
Ironically, basing a song on a true story does not guarantee that the song will come across as real believable.

It’s not important whether or not the story actually did happen in real life; what’s important is for the writer to convince the audience that the situation did or could happen.
The situation and the behaviour of the characters must make logical and emotional sense to the audience.