How To Write a Song on the Piano
If you are an especially creative musician, you might have started to learn how to play the piano so that you could make your own music, and write the songs that you hear running through your head. The more you learn about the piano and how the notes work together to create the music, the better prepared you will be to put those combinations to work for you in new ways, creating new songs. There are a few different strategies that you can use to write songs on the piano, and once you have experimented a little bit, you will find one that feels the most natural for you and gives you the results that you want.
One way to write a song on the piano is to use lyrics to determine the flow of a melody. If you already have lyrics written for your song, you might use the piano to play around with a few different combinations and choose the one that you like the best to fit with the words that you have chosen. Many famous singers have partnerships with songwriters that write the lyrics for them, then turn them over to the piano player to develop the music around them. This may be an option for you if you have already written the words that you want to go with your song, or if you want to set written literature of some kind, a poem for example, to original music. For practice, you can even use the lyrics of a song that you already know, and simply change the music.
Another way is to create a song in your mind, where the melody (with or without words) has already taken shape in your head so that you have a basic idea how you would like for it to sound. The next step is to experiment with the notes of the piano until you find the notes that you would like to use to form the melody, and write them down. Unless you have an exceptional ear for music, you will probably have to use some trial and error to discover the right sequence that matches what you hear in your head. You may even find a combination that isn't what you expected it to be that you like better, and choose to keep that as part of the melody instead, and that is just fine. There is no wrong answer when creating your own song!
If you don't have lyrics already written, or don't plan to include any words in your song (plenty of songs written for piano have no words at all), then you are free to choose any notes that you want, in any rhythm that you like, in order to compose your song. This is a great way for a musician to start writing a first song. For a little help, pay attention to the way that songs on the radio are organized, for example how many verses and chorus sections there are, and in what order. How are transitions introduced? How are the versus different? How are they similar? You have probably listened to your favorite songs dozens of times, but you probably have never analyzed them in this way. Having a general knowledge of the structure of modern songs will give you a great starting place. Once you have the music in place the way you want it, you can add words that match the melody line, if you choose, or leave it as simply an instrumental composition.
After you have written down a melody, you can use the notes of the melody to build a harmony line underneath the main melody. Use your left hand to reinforce important notes in the melody, and play chords that sound good while that part of the melody line is playing. Once you have spent some time on your melody and harmony, your song is complete! Whatever method you choose to write your song, you should try and be as accurate as possible when notating the song. In the beginning, it may seem easier to simply write the letters of the note names, and not try to notate the values of the notes themselves (half note, quarter note, etc). This method is fine for practicing developing melody lines, but it will be very difficult to recreate the song that you composed a few days later, without correct notation. You should also keep in mind that proper music notation is necessary if you want other musicians to be able to play the song that you have written.
If you're looking to write in a certain style of music you may want to look into jazz music on the piano, or blues music on the piano. Knowing your basic note values and basic rest values are also essential to your success in writing a song on piano.