It is almost common knowledge that songs are very powerful. They have the power to change moods and even to influence. This is especially true for any song that has a very forceful sound and powerful lyrics. Most often these come in the form of a rock song. Rock music is a genre which doesn't quite appeal to everybody, but nevertheless still has a following in virtually any demographic.

Rock music seems to appeal mostly to people who are in touch with their rebellious side. Why is this? Rebellion, aggression and similar emotions are often associated with fast heavy beats and loud sounds. One can even say that these emotions are brought about by such. In any case, this style of music is often a perfect match for lyrics which deal with strong emotions. While there are definitely a lot of rock songs which deliver a  positive message, most are not afraid to delve into topics which are considered negative and even taboo by a lot of people.

There are a lot of sub genres of rock, but basically a rock song, as mentioned earlier must have the following:

• Hard-hitting beats, typically used in an upbeat and steady rhythm
• Loud sounds
• Lyrics which are meant to evoke strong emotions

To achieve these, a typical rock group will usually consist of a drummer, a bassist, a guitarist and a singer. This kind of setup is more or less a streamlined version derived from a classical orchestra, which has a percussion, melody and a rhythm section. This band setup can deliver an aggressive and loud sound while still maintaining a musical quality.
The loudest in the band will often be the drummer. His job is to create steady, pounding beats which the bassist can lay a bass line on.

Often, a bassist is required to make a nice groove which listeners can sway and even dance to. While groove is still important for a rock bassist, the focus for his is more on laying thick and solid note foundations which the guitarist can lay a melody on, especially when a rhythm guitarist is not present in the band. The bass is often considered the most unglamorous position in the band since the sound is not as noticeable compared to the other instruments.
The guitarist is in charge of making the melody and the harmony and is often next in line to the vocalist in the spotlight. Most rock songs have a part where the guitarist breaks out screaming melodic lines. This is called the solo or lead part.

Now while it is definitely good to have a vocalist who has a good tone, it is often, not a requirement for a rock band. In fact, a rough, raspy or shrieking voice is often expected from a rock vocalist.

These are some of the elements which are essential in making a rock song. Although music is an art and there really are no rules in making a song, these are some things which you can use to give your song a "rock" feel.