When you are writing a song, it's already music and you can be proud of it. As with any art form, music is very personal and different from person to person. Feel free to experiment with it. For the whole writing it down and arrangement part, just learn the basics of chords. You honestly don't need much of it in the beginning. Try out what sounds best to you. It might take some time to figure that out, but once you get it, it's not too hard.

Talk Doctor Online in Bissoy App